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Thread ID: 51116 2004-11-12 02:56:00 OT-NZCA MATH Dally (6292) Press F1
Post ID Timestamp Content User
290852 2004-11-12 08:22:00 Its just common sense tho, its not all number crunching, there isn't 590 or 600 sports at the olympics. MrBeef (342)
290853 2004-11-12 08:25:00 My mistake

This
17.5x times (x + 10) actually simplifies to 17.5 times x squared plus 27.5x

should have been this
17.5x times (x + 10) actually simplifies to 17.5 times x squared plus 175x


In repsonse to somebody

> Ave Comp. per sport 1964 = X
> Ave Comp per sport 2004 = Y
> Number of sports 1964 = A
> Number of sports 2004 = B
>
> BY = 10500
> B x (3.5X) = 10500
> B x 3.5(5A) = 10500
> A+10 x 3.5(5A) = 10500
> (A+10) x 17.5A = 10500
> 17.5A^2 + 175A = 10500
> A^2 + 10A = 600
> A^2 + 10A -600 = 0
> Factorise
> (A+30)(A-20) = 0
> solve = -30 or 20
> since cannot be -ve, then must be +20
>
> So answer = 20. And I think this works (I substituted
> it back in to check)

how does B = A + 10 if B = 600 and A = 20? 		andrew93 (249)
290854 2004-11-12 08:33:00 Come on guys - I would like someone to explain to me how you can have 600 sports at the 2004 Olympics (per the first post) and have ten less at the 1964 games (again per the first post) and come up with the number 20. So far the 2 responses advocating +20 are not self-consistent, they contradict themselves so therefore cannot be correct. 600 less 10 does not equal 20. andrew93 (249)
290855 2004-11-12 08:46:00 At the Olympic Games 40years ago, the average number of competitors per sport was 5 times the number of sports played.
*so 5A = 100

In 2004 the average number of competitors per sport was 3.5 times greater than 40 years ago.
*so 100x3.5 = 350

In 2004 there were 10 more sports than there were 40 years ago.
*so sports in 2004 = 20+10 = 30

At the 2004 Olympic Games there were 10500 competitors.
30x350 = 10500.

It works 		somebody (208)
290856 2004-11-12 08:47:00 At the Olympic Games 40years ago, the average number of competitors per sport was 5 times the number of sports played.
*so 5A = 100

In 2004 the average number of competitors per sport was 3.5 times greater than 40 years ago.
*so 100x3.5 = 350

In 2004 there were 10 more sports than there were 40 years ago.
*so sports in 2004 = 20+10 = 30

At the 2004 Olympic Games there were 10500 competitors.
30x350 = 10500.

It works 		somebody (208)
290857 2004-11-12 08:50:00 Andrew93
In 1964 there were 20 sports
Average number of competitors in each sport = 100
Number of sports times average equals 2000 competitors
2004 had 30 sports
Average number of competitors in each sport = 350
Numbner of sports times average = 350x30 =10500
If this does not convince you that 20 is the right answer nothing will 		Dally (6292)
290858 2004-11-12 08:50:00 > At the Olympic Games 40years ago, the average number
> of competitors per sport was 5 times the number of
> sports played.
> *so 5A = 100
>
> In 2004 the average number of competitors per sport
> was 3.5 times greater than 40 years ago.
> *so 100x3.5 = 350
>
> In 2004 there were 10 more sports than there were 40
> years ago.
> *so sports in 2004 = 20+10 = 30
>
> At the 2004 Olympic Games there were 10500
> competitors.
> 30x350 = 10500.
>
> It works

Or to word it slightly differently:
In 2004 the average number of competitors per sport was 3.5 times greater than 40 years ago.
*so 100x3.5 = 350

Number of TOTAL competitors = number of sports * ave number of competitor per sport

At the 2004 Olympic Games there were 10500 competitors.
so 10500 = 350 x B
therefore B = 30

And, B = A + 10 = 30 		somebody (208)
290859 2004-11-12 08:52:00 > At the Olympic Games 40years ago, the average number
> of competitors per sport was 5 times the number of
> sports played.
> *so 5A = 100
>
> In 2004 the average number of competitors per sport
> was 3.5 times greater than 40 years ago.
> *so 100x3.5 = 350
>
> In 2004 there were 10 more sports than there were 40
> years ago.
> *so sports in 2004 = 20+10 = 30
>
> At the 2004 Olympic Games there were 10500
> competitors.
> 30x350 = 10500.
>
> It works

Or to word it slightly differently:
In 2004 the average number of competitors per sport was 3.5 times greater than 40 years ago.
*so 100x3.5 = 350

Number of TOTAL competitors = number of sports * ave number of competitor per sport

At the 2004 Olympic Games there were 10500 competitors.
so 10500 = 350 x B
therefore B = 30

And, B = A + 10 = 30 		somebody (208)
290860 2004-11-12 08:57:00 D'Oh!

I worked out my mistake while you guys were doing your posts. I had *incorrectly* read the average competitors at the '64 games as being 5, not 5 times the number of games.

Oops - looks like the old saying is true about tricks and old dogs.

**Slinks off in embarassment never to return to PF1 again** 		andrew93 (249)
290861 2004-11-12 08:59:00 Don't worry... everyone has bad days - as long as you don't make those mistakes in the exams, then we forgive you:D somebody (208)
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