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Thread ID: 51116 2004-11-12 02:56:00 OT-NZCA MATH Dally (6292) Press F1
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290822 2004-11-12 02:56:00 Here's a nice little question from yesterdays math paper
At the Olympic Games 40years ago, the average number of competitors per sport was 5 times the number of sports played.
In 2004 there were 10 more sports than there were 40 years ago.
In 2004 the average number of competitors per sport was 3.5 times greater than 40 years ago.
At the 2004 Olympic Games there were 10500 competitors.
Write an equation to model this and find the number of sports played at Olympic games 40 years ago.
Dally (6292)
290823 2004-11-12 03:02:00 Did that question yesterday.

Cant remeber what I put though :(
george12 (7)
290824 2004-11-12 03:16:00 simple algebra (wait till u get to calculus...)


Set:
Competitors in 1964 (40 yrs ago) as X
Sports in 1964 as Y

Competitors in 2004 as A
Sports in 04 as B

then, use these to replace each statement:

eg, Competitiors in 64 = 5 times Sports in 64
so, X=5*Y

B=Y+10

A=3.5*X

A=10500

now, this is where the fun starts...
fergie (424)
290825 2004-11-12 03:19:00 dont forget however fergie that all you have worked out with your first equation is the average number of competitors per sport, which is almost useless without knowing how many sports there are, i think this is one of the excellences i didnt do (along with that geometic reasoning one that can go jump.....) lagbort (5041)
290826 2004-11-12 03:24:00 arh, sorry about that, had to see what you had to find out...
anyway, we continue...

So we wanna find Y

we can find X from 10500=3.5*X
And we no X=5Y so chuck this into X the equation above to get rid of X, so it becomes:

10500=3.5*5Y
this is the model you're asked to find.

but it can be rearranged to:
Y=10500 / 17.5
which is probably what you needed, then, chuck that in calc, and you get
Y=600

hmm, that seems far to high! 600 sports in the olympics...
See, i hate questions phrased like this, they try to make it more 'fun' by relating it to real life events, and then the answer doesn't make any sense.
I just rechecked and everything works...

So yea, i get 600, but i've probably stuffed up at the start...
Does this refresh ya memory anyone? what you get
fergie (424)
290827 2004-11-12 04:04:00 Fergie - You are a long way from the right answer - try again and it doesn't need calculus - it is as you said simple algebra Dally (6292)
290828 2004-11-12 04:05:00 i got 600 and i thought that i was wrong - 600 is a bit high but i guess they will make it like that , yet i found graphs really easy and everyone in my school said it was hard ApeNz (4220)
290829 2004-11-12 04:30:00 I didn' t sit the exam just supervised it - an oldie who likes math. The reason I put up this post was because I have heard a lot of criticism about NCEA but I thought the math at least was well structured with each booklet starting with simple questions and progressing to relative difficult at the end. Dally (6292)
290830 2004-11-12 05:38:00 The problem with this structure from what I've seen/heard, is there are a huge number of students who simply go in and just do the easier "Achieved" questions, and don't even bother to do the more challenging Merit/Excellence ones. For many a "pass is a pass".

In saying that, some of the NCEA questions are really poory worded. Sometimes the answer can be wrong simply because of the interpretation of badly written english. I also find that the Merit/Excellence questions are more about interpreting english, rather than actually challenging mathematical knowledge, although they do get more difficult as you move up the marksheet.
somebody (208)
290831 2004-11-12 05:41:00 poor worded - you would think a person who knew english for 10 minutes wrote them - sometimes i have to read a question 5 times just to get it ApeNz (4220)
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