View Full Version : Maths Revision

Gum Digger

28-10-2004, 06:23 PM

Hi

Iam looking for some cheap Maths tutions, does anyone know off any?.

I just want to revise bcoz i cant study much at home.

so help me plze

Valerie

28-10-2004, 07:01 PM

At what level??

http://www.mathsisfun.com/

V...

Prescott

28-10-2004, 08:14 PM

have you tried those maths revsion books?, its got all the past school c and ncea exam questions, do all of them and it will be an advantage, they are avalable for lv1,2,3 the books called for example 2003 level 2 maths revsion book made by really useful resources(this is what the book is made by i think)

HTH

DangerousDave

28-10-2004, 08:39 PM

> http://www.mathsisfun.com/

those people are lying!

- David

Growly

28-10-2004, 08:41 PM

Speaking of how badly NCEA questions are worded....

Got this today (roughly):

John bought a car. He paid a 30% deposit and borrowed the remaining 70%. He will pay the money back using two methods:

1) He pays his parents $45 a month for two years.

2) He has a deal with the card dealer that means he doesn't pay anything for two years, after which he pays a lumpsome which includes 10.5% interest on the amount owing at the start of the first year, and then the further 10.5% on the amount owing at the beginning of the second year. The lumpsome he paid was $2992.

What was the original price of the car?

Now, one would wonder where 1) would enter into it.

If he has a deal with the car dealer to pay back 70% of the car (the amount he borrowed), then why the hell does his mum enter the equation?

The answer was (amount he paid his mum + amount for car pre the interest)/0.7.

No one in our class understood this, not even our teacher.

Prescott

28-10-2004, 08:44 PM

what level u doing growly

Susan B

29-10-2004, 09:36 AM

> If he has a deal with the car dealer to pay back 70% of the car (the amount he borrowed), then why the hell does his mum enter the equation?

Maybe he borrowed the 30% deposit from his parents?

They are quite good at leaving out "relevant" information and leaving you to use your imagination sometimes. ;-)

~~~~~ s y ~~~~~

29-10-2004, 10:03 AM

> Iam looking for some cheap Maths tutions, does anyone

> know off any?.

> I just want to revise bcoz i cant study much at

> home.

> so help me plze

I presume you want a private tutor? As you say you can't study much at home.... and according to your profile.. you're in Samoa!!??!?!/

Please confirm what year level you are and where exactly you are in the world....

Billy T

29-10-2004, 10:09 AM

Last I knew he was in Mt Roskill, Auckland, and probably still is.

Cheers

Billy 8-{)

~~~~~ s y ~~~~~

29-10-2004, 10:18 AM

> Speaking of how badly NCEA questions are worded....

> No one in our class understood this, not even our

> teacher.

Disclaimer: I don't mean any offence. Just expressing my view as many forum users have said is allowed :p

For a starter, the teacher needs to sacked. Even my third form brother did it in less than two minutes! [yes he did have a calculator]. If this is what your complaining about, then don't even think about IGCSE. Personally, I see NCEA questions as being great, real life problems.. etc. IGCSE has questions usually 8 parts wrong. If you stuff it up at the start.. you're stuffed. They mislead you more than anything else.

This is soooooooooooooo easy! Look....

1) He gets $45 from his mum for 24 months (2 years)... so

45x24=$1080

2) He pays $2992 in the end after two paying two lots of interest... so

2992/1.105/1.105=$2450.40

So in total, 70% of the cost is made up of $1080+$2450.40=$3530.40

Now, to find 100% you go $3530.40/0.7=$5043.43

Bingo! I don't see whats so confusing!

I can understand why your class can't understand.. because your teacher can't! The only negative thing about NCEA is its marking system, and international reputation so far. Ha... ! IGCSE with that kind of teacher? Dream on....

I shall go enrol for teachers college for next year.... muwhahah :D

RobbyW

29-10-2004, 03:44 PM

> For a starter, the teacher needs to sacked. Even my

> third form brother did it in less than two minutes!

> [yes he did have a calculator]. If this is what your

> complaining about, then don't even think about IGCSE.

> Personally, I see NCEA questions as being great, real

> life problems.. etc. IGCSE has questions usually 8

> parts wrong. If you stuff it up at the start.. you're

> stuffed. They mislead you more than anything else.

>

> This is soooooooooooooo easy! Look....

>

> 1) He gets $45 from his mum for 24 months (2

> years)... so

> 45x24=$1080

> 2) He pays $2992 in the end after two paying two lots

> of interest... so

> 2992/1.105/1.105=$2450.40

>

> So in total, 70% of the cost is made up of

> $1080+$2450.40=$3530.40

>

> Now, to find 100% you go

> $3530.40/0.7=$5043.43

>

> Bingo! I don't see whats so confusing!

>

> I can understand why your class can't understand..

> because your teacher can't! IGCSE with that kind of

> teacher? Dream on....

>

> I shall go enrol for teachers college for next

> year.... muwhahah :D

IGSE huh? LOL!

For starters: He's not getting the money from his mum monthly,the 45/month is for repayments.

The confusing part is that the question is a limp cabbage! It doesn't specifically say where the deposit or the lump sum after the two years come from!

Growly

29-10-2004, 03:48 PM

Disclaimer: I also mean no offence by my post - I just wish to point how incredibly horrid this question is.

I appreciate your attempt to educate me, but it is unneeded - I know maths - the problem is in the logic of the question.

He borrowed 70% to pay the car, after paying a 30% deposit. Therefore he owes the car dealer 70% of the car.

>Bingo! I don't see whats so confusing!

Probably because you read the question incorrectly - he doesn't receive money from his parents, he pays them money.

Which brings me to the point - if he owes the car dealer 70% of the car, and he has a deal with them to pay back 70% of the car, then why does he have to pay his parents?

Furthermore, if he owes the car dealer 70%, then his deal would be to pay back the remainder of the car in a lumpsome, so he will pay them back 70% of car with interest.

As you correctly calculated, this is 2992/(1.105^2)=$2450.40.

Therefore, as this is the 70% of the car that he owed the dealer, then it is the 70% of the car that he needs to pay back. Therefore the car should cost $2450.40/0.7=$3500.57.

Not as you say $5043.43. Infact the marketing schedule said we're both wrong.

The stupidest thing about the question is that his parents don't enter into the equation. Can someone give me a good explanation why how much he pays his parents must be added to how much he pays the car yard?

I mean wtf?

>I can understand why your class can't understand..

Are you sure you can understand? A friend was telling me today that IGCSE isn't all it's cracked up to be - sure I want to do it, it's better than NCEA - but you only need like three tenses to pass French or Japanese? Pfft.

I implore you all to not take said questions lightly, study, study study - you'll only get these right with experience.

Growly

29-10-2004, 03:52 PM

Note: "Infact the marketing schedule said we're both wrong." is a deliberate attempt to lower NCEA to nothing more than face value to show we have an education system (a bit harsh).

Oh, and I'm in 5th form....

~~~~~ s y ~~~~~

29-10-2004, 04:39 PM

Ok, Growly. Always nice to have feedback. Besides I don't even know if thats right :p..

Do you mind posting the answer? And what paper is it from, year date.. etc. Or links?

techie_fanatic

29-10-2004, 04:45 PM

> The answer was (amount he paid his mum + amount

> for car pre the interest)/0.7.

i dont understand the irony in this. u said ~~sy~~~ was wrong even though u already had this. according to what u said as per above and sys working i see nothing wrong with what sy did.

i would be interested to see the workings behind this

... or maybe im just not as good at maths as i should be... :(

techie_fanatic

29-10-2004, 04:57 PM

AH! i SEE where your coming from Robyn... yes, hes not receiving is he!!! my bad :(

Oh well.. I think I've read it enough times to say quits. nice little exercise for the day.

~~~~~ s y ~~~~~

29-10-2004, 05:04 PM

Sorry your quite right. I did read the question wrong and thus told my bro the wrong question. See what happens when your on too much study leave ;-)

And yes, I still agree NCEA 'is not the best' But I'd say the answer is incorrect. I'd be interested to see the q/a as I mentioned before.

My bad, friends again! :p

Billy T

29-10-2004, 05:42 PM

>John bought a car. He paid a 30% deposit and borrowed the remaining 70%. He will pay the money back using two methods:

I'm no maths wiz, but I can't see how anybody can do other than get one of several correct answers here, there are too many unanswered questions, for example:

1) Did he borrow the 30% from his parents to make the deposit?

2) If not, did he have the deposit saved, and the borrowing from his parents was in fact part of the 70%?

3) You only know how much he owed the dealer.

I suspect that the original question may have contained just a little more information.

Cheers

Billy 8-{)

Shaun Minfie

29-10-2004, 05:50 PM

What colour is the car?

Growly

29-10-2004, 06:05 PM

>1) Did he borrow the 30% from his parents to make the deposit?

>2) If not, did he have the deposit saved, and the borrowing from his parents was in fact part of the 70%?

>3) You only know how much he owed the dealer.

>I suspect that the original question may have contained just a little more information.

It contained no extra information. That's the whole point.

>i dont understand the irony in this. u said ~~sy~~~ was wrong even though u already had this. according to what u said as per above and sys working i see nothing wrong with what sy did.

First of all, I don't see any irony at all - second of all, I never came to the conclusion that the answer was (amount he paid his mum + amount for car pre the interest)/0.7 - my question was how on earth could you deduce that from such a poorly worded question.

This is not a test of wits. I wanted to show you how stupid these questions can be. The fact that you are defending yourselves and claiming that you know the answer is beyond me...

The answer, according to the marking schedule, was (amount he paid his mum + amount for car pre the interest)/0.7. [i]What I and many others want to know is why it is mount he paid his mum + amount for car pre the interest, when the amount he paid is mum is irrelevant and doesn't even enter into it, based on what we know. If you can prove that how much he owes his mum is relevant to the cost of the car, then please patronise me all you want and tell me how. Until then, I think it's safe to say that the question sucks. It always sucked.

Sorry for the off-topicness, but I originally wanted to show how stupid it was.

Growly

29-10-2004, 06:10 PM

Grrrr. Sorry about italics.

I see now in hindsight that my earlier post gave across the message that we understood the question and didn't know the maths. I'd like to clarify that, again, right now by saying that we did not understand the question, because of it's sheer illogical nature.

They never told us what his mum has to do with anything. Not once.

I do not know which paper this is from - it was collated into a book. Now whether it was misprinted or whatever is beside the point - I'm trying to prove how horrible a situation we students face.

Dally

29-10-2004, 07:05 PM

Looks a pretty straight forward question to me. He owes 70% of the cars price after paying his deposit. This he pays back using two ways - $45 per month to his parents obviously interest free and the rest to the car dealer involving the stated interest. The marking schedule's answer is plainly the correct one. The two parts the repayment are reasonably clear.

Growly

29-10-2004, 08:26 PM

Why does he pay his parents?

Growly

29-10-2004, 08:28 PM

Or to put it another way, why does he not pay the 70% straight back to the dealer?

Bletch

29-10-2004, 09:03 PM

I agree that the question is badly worded, but with a bit of common sense it it possible to work out what is required. The only information 'missing' is that the money he paid his parents was destined for the car dealer. This information is easy to deduce, because in the context of the question he would not be paying his parents for anything other than the car. Then, if you think about it some more - they state that "He will pay the money back using two methods". The only two methods listed are the parents and the dealer. Therefore ( all answers rounded to 2dp):

pays parents $40/month for 2 yrs

$2995 is the lumpsum including 2 yrs interest.

To work out the interest:

$2995 / 110.5 = $27.10 (break into 1% blocks)

$27.10 X 10.5 = $284.55 (this is the interest for the 2nd year)

$2995 - $284.55 = $2710.45 (the lumpsum with 1 year interest)

$2710.45 / 110.5 = $24.53 (break into 1% blocks)

$24.53 X 10.5 = $257.57 (interest for second year)

$2710.45 - 257.57 = $2452.88 (the lump summ less the interest)

Now we add the lump sum to what he has paid his parents:

$2452.88 + $(45 X 24)

$2452.88 + $1080

TOTAL = $3532.88

Therefore the original cost of the car was $3532.88.

Happy now? Yes the question was badly worded, but with a bit of common sense it is easy to solve.

Bletch

Bletch

29-10-2004, 09:04 PM

> Or to put it another way, why does he not pay the 70%

> straight back to the dealer?

That's not the point of the question. The aim was to make you think about it in a different way, not necessarily the most sensible one.

Bletch

29-10-2004, 09:05 PM

I agree with SY - fire the teacher.

Bletch

29-10-2004, 09:10 PM

> $2995 is the lumpsum including 2 yrs interest.

>

> To work out the interest:

> $2995 / 110.5 = $27.10 (break into 1% blocks)

> $27.10 X 10.5 = $284.55 (this is the interest

> for the 2nd year)

>

> $2995 - $284.55 = $2710.45 (the lumpsum with 1

> year interest)

> $2710.45 / 110.5 = $24.53 (break into 1%

> blocks)

> $24.53 X 10.5 = $257.57 (interest for second

> year)

> $2710.45 - 257.57 = $2452.88 (the lump summ

> less the interest)

>

> Now we add the lump sum to what he has paid his

> parents:

> $2452.88 + $(45 X 24)

> $2452.88 + $1080

> TOTAL = $3532.88

Sorry about the final answer - I worked out the problem using $2995 (not $2992) as the lumpsum. This means that the final answer will be slightly off, however the logic is correct

Bletch

29-10-2004, 09:15 PM

> >John bought a car. He paid a 30% deposit and

> borrowed the remaining 70%. He will pay the money

> back using two methods:

>

> I'm no maths wiz, but I can't see how anybody can do

> other than get one of several correct answers here,

> there are too many unanswered questions, for

> example:

>

> 1) Did he borrow the 30% from his parents to make the

> deposit?

No, the question says "He paid a 30% deposit". Ergo, the 30% was not borrowed. It says that the remaining 70% was borrowed.

>

> 2) If not, did he have the deposit saved, and the

> borrowing from his parents was in fact part of the

> 70%?

Yes.

>

> 3) You only know how much he owed the dealer.

You also know how much the original 30% was. You have all the info required to solve it, it just requires a bit of common sense (no offense)

>

> I suspect that the original question may have

> contained just a little more information.

I don't think it did. It's not needed.

Bletch

beetle

29-10-2004, 09:32 PM

Maybe his parents were the car dealers?

and he had to pay them back - being the car dealer.

otherwise this is totally confusing and i cant see the point in this question but then i am not good at maths.

beetle

Bletch

29-10-2004, 09:34 PM

Growly,

> As you incorrectly calculated, this is

> 2992/(1.105^2)=$2450.40.

You can't work out the interest this way. This is because it is not a lump sum interest, it is a compounding interest. What you need to do is take off the second year's interest, then the first years.

[b]$2992 / 1.105 = $2707.69

$2707.69 / 1.105 = $2450.40

Bletch

29-10-2004, 09:36 PM

Does someone want me to do a really simple, step by step analysis of the problem which shows how to get all of the info out of the original question? I can post this on the thread tonight if ppl want.

beetle

29-10-2004, 09:37 PM

Oh had another thought, maybe his parents are saving the money for him so he can pay a lump sum each year for his interest and final payments?

so he has the money already, and no panics to find it later?

beetle ?:|

Bletch

29-10-2004, 09:41 PM

He doesn't pay two lump sums. The only lump sum he pays is at the end, including 2 years compounding interest. He can't be getting the parents to save the money for him, because it says that he pays back the 70% in two ways. Therefore the parents cannot be saving for the lump sum

george12

29-10-2004, 10:35 PM

You seem right Bletch, and I can follow your logic.

However, it seems blatently obvious to me that if you are the only one here who can even understand what the question is asking, then it is badly worded.

Any question that can cause so much debate over the meaning is very poorly constructed. I don't really think that making the question confusing is a fair way to test common sense (if that's what they were playing at, if not they were just dumb).

In fact (and my [highly skilled] maths teacher agrees) a lot of NCEA 1 questions are poorly worded and ambiguous. In fact there was one Excellence question made, last year I beleive, that 0% of NZ got correct. That is of course rounded down from 0.1823865 or something, but it is still showing how bad a question it must have been (a much higher percentage is supposed to get excellence).

I didn't get this one at the start either, and I consider myself not bad at maths. I agree with Growly on this one.

George

Bletch

29-10-2004, 10:40 PM

George, I fully agree with you. A question like this does not belong in a level 1 NCEA test. Do you know if it was an E, M, or A question? Here is the full explaination, which I hope will help you understand it.

Here is the full explaination of the problem. All answers rounded to 2 decimal places.

John bought a car.

STUFF WE KNOW:

1) He pays parents $45/month for 2 years. This is $45 * 24 months. This payment MUST go towards the 70%,

because it says that he paid (not borrowed) the 30%. The total amount was $1080.

2) He pays a lumpsum to the car dealer. This sum is $2992, and consists of: 70% of car + 10.5% interest + another

10.5% interest.

3) He has already paid off 30% of the car.

Summary of what we know:

1) he paid parents $1080.

2) He paid the dealer $2992 lumpsum.

3) He paid the dealer a lumpsum deposit of 30% of the original car price.

STEP ONE - REMOVE INTEREST FROM LUMP SUM

$2992 includes compounding interest, so we must remove 10.5% for each time interest was calculated (i.e. we

can't simply take off 10.5% * 2)

100% = 100/100 = 1

10.5% = 10.5/100 = 0.105

1 + 0.105 = 1.105

$2995 / 1.105 = $2710.41 (this removes the second year of interest)

$2710.41 /1.105 = $2452.86 (this removes the first year of interest)

Therefore the lum sum without interest is $2452.86. This is 70% of the total cost of the car, less what he paid his

parents.

STEP TWO - THE CONFUSING BIT

We know this because the problem states that he paid the borrowed money back in two ways - to his parents

($1080) and the rest as a lump sum to the dealer. The problem occurs when we try to consider what happened to

the money he paid his parents. Obviously the money was not paid to the dealer immediately, because John had an

agreement in which he paid nothing for 2 years. However, the problem fails to tell us whether the money he pays his

parents is included in the lump sum payment. Using common sense, we can determine that the money paid to the

parents is not part of the lumpsum payment, because it cannot be a separate payment method if it is merely

an accessory to the another method. The money paid to the parents obviously is for the car dealer, as it is stated as

a payment option. Therefore, the payments are separate from the lump sum payment, but still go towards paying off

the car. As nothing is mentioned about interest in relation to these payments, we can safely assume that this is

something we do not have to worry about.

STEP THREE - WHERE THE MONEY WENT

30% was paid as a deposit

$2452.86 was paid as a lump sum

$1080 was paid to the parents, and then somehow got to the car dealer.

10.5% interest was calculated on two occasions. As we have removed it from the lump sum, and it is not relevant to

the original price of the car, we can safely forget about it.

STEP FOUR - BRINGING IT ALL TOGETHER

The money is divided as follows:

30% - initial deposit

$2452.86 lump sum

$1080 paid to parents

To work out the cost of the car, we first add the lump sum to the money paid to the parents:

$2452.86 + $1080 = $3532.86.

Because this is only 70% of the price of the car, we then divide it by 70/100 (0.7).

$3532.86 / 0.7 = $5046.94

This gives us 100% of the car's original cost, before interest.

STEP FIVE - THE FINAL ANSWER

The final answer is $5046.94.

george12

29-10-2004, 10:57 PM

That was a beatiful explanation. You should be a maths teacher :).

> Do you know if it was an E, M, or A question?

I would guess 'E'.

I do understand that the question is possible, and in fact with a ... little bit of help ... anyone can understand it.

But when I first saw it I didn't get it, Growly didn't get it, in fact nobody but you did. For that you deserve congratulations, but that is not the point.

Out of curiosity (if you don't mind), what year are you in (if you're at school)? Because I imagine you might be in a much higher year than Level 1, in which case nobody here doing Level 1 got the question correct.

Do you think NZQA test their questions? Or just write them and hope they work?

George

Bletch

29-10-2004, 11:03 PM

I am in year 12 (NCEA Level 2). From what I have seen of level 1 NCEA questions, I think that the people from NZQA don't test them, or if they do then they must have very narrow thinking.

george12

29-10-2004, 11:15 PM

It's rather strange:

You would think that they would test the questions, it seems absurd that they might not, but at the same time if they do test one wonders how some of the questions I've seen slip through.

Perhaps the people that write them check them too.

"I don't even need to read the question, I know it off by heart. After all, I did write the bloody thing!" - Some NZQA Guy

Now that would explain some things.

George

Bletch

29-10-2004, 11:19 PM

Nice quote, lol!:D

What I think they should do is test them on a sample of students (maybe 200 or so) and see how the students manage. If there is mass confusion, then something is obviously wrong with the question.

Rob99

29-10-2004, 11:20 PM

I think this is a trick question, why would you pay back two lones for one car.

So ignore option two and work with the easy option 1.

45*24=1080 which is 70% of the total.

My workings from here might not be what you guys are learning but they satisfy me, so here goes:

1080/7=154.286 this is 10% of the total cost.

154.286*10=1542.86 this should be 100%.

My answer would be $1542.86

Bletch

29-10-2004, 11:26 PM

> I think this is a trick question, why would you pay

> back two lones for one car.

> So ignore option two and work with the easy option

panic!! You can't do this!

> 1.

> 45*24=1080 which is 70% of the total.

[b]It's not, you have to remember the $2992 lump sum he paid to the dealer

> My workings from here might not be what you guys are

> learning but they satisfy me, so here goes:

> 1080/7=154.286 this is 10% of the total cost.

> 154.286*10=1542.86 this should be 100%.

why do you do it this way? You can save time and use 0.7:

1080/0.7 = 100% total cost. But anyway, this answer is wrong.

>

> My answer would be $1542.86

It might be, but what happened to the rest of the problem? No offense intended, but you are missing a fairly vital part.

Bletch

29-10-2004, 11:27 PM

sorry about the bold text, I forgot to turn it off.

Rob99

29-10-2004, 11:32 PM

Or if I had to consider option 2 as well my answer would be: $4966.67

Bletch

29-10-2004, 11:33 PM

how did you get this? Can you show some steps?

Rob99

29-10-2004, 11:34 PM

>panic!! You can't do this!

I can do what I like, even get it wrong if I wish.

Bletch

29-10-2004, 11:38 PM

Fair enough, my bad. What I meant was that according to the generally accepted rules of mathematics, you cannot usually disregard conditions and still obtain a correct answer.

Rob99

29-10-2004, 11:41 PM

I should have writen it down but:

$2992-10.5%=2677.84

2677.84-10.5%=2396.6668

2396.6668+1080=3476.6668

3476.6668/7=496.6666........

496.6666........*10=$4966.67

Rob99

29-10-2004, 11:45 PM

$2992-10.5%=2677.84

2677.84-10.5%=2396.6668

2396.6668+1080=3476.6 668

3476.6668/7=496.6666........

496.6666........*10=$4966.67

woops I forgot the 1080 bit so:

4966.67+1080=$6046.67

Bletch

29-10-2004, 11:48 PM

OK, I think I understand your problem. When you are using your calculator, are you pressing: "2 9 9 2 - 1 0 . 5 %"? You can's do this on a normal calculator, the % button does other wierd things. What you need to do is "2 9 9 2 / 1 . 1 0 5". This should give you 2707.69 after removing the interest for the first time.

I am going to bed now, will check this thread after lunch tomorrow afternoon.

Bletch

Bletch

29-10-2004, 11:53 PM

>You can's do this on a normal calculator,

sorry, should be can't do this on a normal...

Growly

30-10-2004, 08:27 AM

>You can't work out the interest this way. This is because it is not a lump sum interest, it is a compounding interest. What you need to do is take off the second year's interest, then the first years.

Yes you can. Pull out your calculator, and do it my way. You'll be surprised I'm guessing to realise the answers are the same. My problem was never with the mathematics involved!

Your logic is plausible, yet, given the amount of information available, possible slightly farfetched. We are all told not to assume anything in any question, so this just adds to our plight. As far as this "common sense" thing goes, would common sense not dictate that the lumpsome he pays the dealer back is 70% of the car with interest? This question is missing something as you said, and without that something we are unable to complete it, because that would be making things up, now wouldn't it?

So let me get this straight - he owes the dealer 70% of the car (with interest added, but it is still the remainder of what's left to be paid). He also owes his parents 45*24=$1080. You are suggesting that one presumes that this money is intended to pay the dealer aswell.

So let's look at the logic again:

He originally paid the dealer 3/10 of the car (deposit). In option two he is paying back 7/10 of the car. THAT MAKES 10/10 = 1 = THE WHOLE CAR. What I don't understand is what common sense dictates that we add the payment to the parents to all of this!

Following your method, we are presuming that the lumpsome paid to the dealer in method two is not all of the money remaning to be paid on the car. Your logic is probably the logic the examiners used, but because of the horribly worded question we do not know in which way to take it. Using common sense, for example, we deduced that method two concerend all of the money owed to dealer after the 30% deposit and so, because the dealer would not give a deal on say 60% of the remainder, this must be all that is owed.

I mean c'mon, in reality which dealer out there gives you a payment plan in which you've paid 30%, and you delay the payment of 60%, and the remaining 10% is up to some random!?

The question is flawed. That is my point. We can discuss common sense but there is always a counter-argument, which makes this question utter crap. So my point stands - no amount of working will make this question plausible or reasonable. Sure it can be done, but in so many different ways that it reaches a level of idiocy unparalled by any other question I've ever faced.

And for the record, my teacher is highly capable - the fault is not hers. You all think you have the answer, but the amount of guessing and presuming you did would not get you marks in the exams (we cannot, for example, deduce that a beam horizontal to a flat ground is parallel).

Pfft, cars.

Dally

30-10-2004, 10:14 AM

Let's explain in simple terms

John sees a car priced $5043.43. He counts his pennies and finds he has 30% of the price as a deposit namely $1513.03.

He goes to his mum and asks if see can help him out. Yes she says - I can lend you $1080 towards the car and you can pay me back at $45 per month for 2 years. That leaves the rest to be borrowed from the dealer $2450.4. Interest will be paid on this in terms of 10.5% immediately equals $2707.69 and then this sum incurs a further 10.5% equalling $2992 lump sum. All this is evident in the question.

Bletch

30-10-2004, 10:56 AM

> >You can't work out the interest this way. This is

> because it is not a lump sum interest, it is a

> compounding interest. What you need to do is take off

> the second year's interest, then the first years.

>

> Yes you can. Pull out your calculator, and do it my

> way. You'll be surprised I'm guessing to realise the

> answers are the same. My problem was never with the

> mathematics involved!

True, for this instance. I admit I did not notice that the answers were the same.

>

> Your logic is plausible, yet, given the amount of

> information available, possible slightly farfetched.

> We are all told not to assume anything in any

> question, so this just adds to our plight.

We are not told to assume anything, but the question is useless unless we do. Therefore we must assume something.

>As far as

> this "common sense" thing goes, would common sense

> not dictate that the lumpsome he pays the dealer

> back is 70% of the car with interest? This

> question is missing something as you said, and

> without that something we are unable to complete it,

> because that would be making things up, now wouldn't

> it?

No, common sense would dictate that they would not put 'the money owed to the parents' in the question unless it related to the question in some way. As the 30% has already been paid, the remaining 70% must contain botht the lump sum less the interest and the money paid to the parents.

> So let me get this straight - he owes the dealer 70%

> of the car (with interest added, but it is still the

> remainder of what's left to be paid). He also owes

> his parents 45*24=$1080. You are suggesting that one

> presumes that this money is intended to pay the

> dealer aswell.

Yes. We assume this because there would be no point putting this in the question if the money was not intended for the dealer.

> So let's look at the logic again:

>

> He originally paid the dealer 3/10 of the car

> (deposit). In option two he is paying back 7/10 of

> the car. THAT MAKES 10/10 = 1 = THE WHOLE CAR. What I

> don't understand is what common sense dictates that

> we add the payment to the parents to all of this!

Because it is part of the question, and the 70% is the only place the money can logically go.

> Following your method, we are presuming that the

> lumpsome paid to the dealer in method two is not

> all of the money remaning to be paid on the car.

Yes.

> Your logic is probably the logic the examiners used,

> but because of the horribly worded question we

> do not know in which way to take it. Using common

> sense, for example, we deduced that method two

> concerend all of the money owed to dealer after

> the 30% deposit and so, because the dealer would

> not give a deal on say 60% of the remainder, this

> must be all that is owed.

How do you figure this? Nowhere[/b[ does it say this, and we cannot simply ignore the money paid to the parents.

> I mean c'mon, in reality which dealer out there gives

> you a payment plan in which you've paid 30%, and you

> delay the payment of 60%, and the remaining 10% is up

> to some random!?

If this was a real-life question, it would never happen. The point is that it was a test question designed to make you think. The NCEA people just made a shocking job of designing the question.

> The question is flawed. That is my point.

I fully agree.

>We can

> discuss common sense but there is always a

> counter-argument, which makes this question utter

> crap.

[b]But, the counter-argument can always be defeated in this question, because to solve it any other way involves leaving out some of the data.

>So my point stands - no amount of working will

> make this question plausible or reasonable. Sure it

> can be done, but in so many different ways that it

> reaches a level of idiocy unparalled by any other

> question I've ever faced.

It can only be done one way that includes all the data, but the wording is such that it makes for a very confusing and ambiguous question.

> And for the record, my teacher is highly capable -

> the fault is not hers.

Noting how much debate this question caused, I'm inclined to agree with you.

>You all think you have the

> answer, but the amount of guessing and presuming you

> did would not get you marks in the exams (we cannot,

> for example, deduce that a beam horizontal to a flat

> ground is parallel).

This would actually get an exam mark, for the reason that it is the only logic method I can find that includes all the data. If anyone can come up with another method that can do this, please say.

> Pfft, cars.

I fully agree!

Bletch

30-10-2004, 10:57 AM

again, sorry for the bold text

george12

30-10-2004, 12:49 PM

I just feel sorry for Gum Digger, who has had his question completely forgotten.

Now here's where I stand:

Bletch: You are 100% correct about the question, and 100% correct in agreeing with all of us (or most) that it is a poorly made question.

Growly: You are 100% correct when it comes to how crap the question is, but Bletch's logic is correct (in terms of how he worked it out).

Seeing as nobody here that is doing Level 1 could correctly answer the question first try in a way that would obtain any credit, I think everbody here must agree as to the quality of the question.

Dally, nice explanation, it makes an ambiguous question look clear and simple. But that doesn't mean it is; shame on you NZQA.

Just to fire the argument back up, $5043.43 is the only acceptable answer as I see it.

George

george12

30-10-2004, 12:53 PM

Oh, and because of rounding I mean that any answer around there is correct. Ie, Bletch's [b]$5046.??[b] (I forgot the decimal places).

Graham L

30-10-2004, 02:02 PM

Why not test questions on a sample of teachers? Then on a sample of "examiners", Then on the ERO?

I am not impressesed with the NCEA system. It looks to be a "manager's" idea of what a teaching factory should be like. Unfortunately, what NZ needs is an education system.

Dally

30-10-2004, 03:10 PM

I used to help run quiz evenings (the ones where you have one minute to answer each quetion) and I liked to throw in the odd math problem just to see the look of horror on some faces. Here's a sample:-

If a brick weighs 10kg plus the weight of half the brick. How much does the brick weigh?

Bletch

30-10-2004, 04:50 PM

> Oh, and because of rounding I mean that any answer

> around there is correct. Ie, Bletch's $5046.??[b]

> (I forgot the decimal places).

Yes, although I also made one other slip-up at the beginning of my workings. I accidentally based the lump sum payment on [b]$2995 instead of $2992, so that plus the rounding will mean my final answer is slightly out. Any answer around that area will probably be correct though, as it is only a $3 error.

Bletch

lagbort

30-10-2004, 04:58 PM

does that brick by any chance weigh 20kg?

(just a random guess using about 30 seconds of algebra :p )

Bletch

30-10-2004, 05:33 PM

> does that brick by any chance weigh 20kg?

> (just a random guess using about 30 seconds of

> algebra :p )

Yes, the brick must weigh 20Kg.

We need to fing 100% of the weight of the brick:

100% = 10Kg + 50%

100% - 50% = 50%

Therefore 10Kg is 50% of the brick's weight.

50% * 2 = 100%

or

10Kg * 2 = 20Kg.

Bletch

Dally

30-10-2004, 06:59 PM

The brick is 20kg. Usually about half the people on quiz nights put 15kg

Growly

31-10-2004, 08:37 PM

>That leaves the rest to be borrowed

Aha! Therein lies the whole problem!

I am not attempting to prove anyone's logic wrong, I am trying to prove that, as you all no doubt agree, the question is shocking - I attack any 'logical' statement about the answer for one reason:

In a sentence, the confusion of many arose from the fact that the correct answer assumed that the mother had, as Dally explained, paid for the car at the beginning, at the same time he made his deposit - while most assumed that by being a deposit, it was the only money exchanged at the beginning.

I don't know about your experiences with marking, but to give this question a mark, no matter how logical the explanation, would make hypocrites of markers. I myself was lowered from Excellence to Merit in an internal because I said that one "selects" a sample, instead of "takes". Granted the can imply different mindsets, but the level of presumption required to take those as the same thing is roughly equal to level required here. You said so yourself Bletch, a whole sentence is implied.

So, no matter what your explanation, NCEA sucks.

Bletch

01-11-2004, 04:10 PM

> I don't know about your experiences with marking, but

> to give this question a mark, no matter how logical

> the explanation, would make hypocrites of markers. I

> myself was lowered from Excellence to Merit in an

> internal because I said that one "selects" a sample,

> instead of "takes". Granted the can imply different

> mindsets, but the level of presumption required to

> take those as the same thing is roughly equal to

> level required here. You said so yourself Bletch, a

> whole sentence is implied.

>

> So, no matter what your explanation, NCEA sucks.

I agree, NCEA sucks :(. However, you must have a really hard internal marking system if you got downgraded only because of that one word choice. Most markers will allow you to use either 'takes' or 'selects' or even another word, as long as it is accurate and the meaning is clear. The only difference between these particular two words is this: 'takes' implies some preocess of harvesting, whereas 'selects' implies that you have chosen your sample, but have not yet harvested it. However for most purposes (including, I guess, your exam) these two words mean more or less the same thing.

Curse bad internal moderation!

Bletch

Growly

01-11-2004, 06:53 PM

>Curse bad internal moderation!

It just makes me want to play some sort of violent first person shooter....

fus1_n

01-11-2004, 06:58 PM

> It just makes me want to play some sort of violent

> first person shooter....

UT 2004 = FUN!!

I have seen cases of people going down from a excellence to a N/A because of one question. In my chemistry mock test I got NA because i missed out a question because of bad page layout (no kidding!!! half the people didn't read the question) if i got that one Q i would have got merit.

:(:(

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