Comments on: QOTW: Fifth Grade Maths

By: Juice

Juice — Tue, 31 Jul 2007 07:48:57 +0000

I absolutely suck at Maths.

By: Josh

Josh — Tue, 31 Jul 2007 00:56:40 +0000

Well, first I subtracted 5 from 20, because we already know that they play both. Next, I subtracted 8 and 11 from 15, separately, to figure out how many people play just squash or tennis. I figured out that 7 people play just tennis and 4 people play just squash. So, I subtracted the sum of the three numbers, 16, from 20 and got 4.

So, the answer is C:4.

(Scrolling through the comments after solving it, I realised that I probably used the least efficient method of solving this. I suck at setting up equations for problems like this. =/)

By: Skye

Skye — Mon, 30 Jul 2007 21:59:06 +0000

Well, 20 people total.

8 don’t play one 11 don’t play the other. So that’s 19. Meaning 1 person doesn’t play either.

However, I’m not sure because of the wording. They say OR and EITHER which infers that they mean either or. Meaning not both. Meaning how many only played one. 5 play both and 1 plays neither so 20-6=14 which isn’t an option.

By: Nan

Nan — Mon, 30 Jul 2007 21:27:13 +0000

On a totally unrelated note I would love to try squash!

(4)

By: Ramsha

Ramsha — Mon, 30 Jul 2007 21:21:36 +0000

Hah, I know the answer, but people’ve guessed already, so I’m late!

Skye, that’s exactly what people do, if they’re not super math geeks!

By: Skye

Skye — Mon, 30 Jul 2007 14:42:37 +0000

Umm, don’t you use the venn diagram to solve questions like these? It makes life a lot easier. :D

By: Julianne

Julianne — Mon, 30 Jul 2007 11:08:53 +0000

Math before 8:00 a.m. Will wonders never cease?

20 = squash players + tennis players + both + neither
20 = S + T + 5 + N
15 = S + T + N
15 = (15-8) + (15-11) + N
15 = 7 + 4 + N
N = 4

By: tam

tam — Mon, 30 Jul 2007 11:02:48 +0000

I found one of your recent comments on melbournemaniac incredibly amusing and did some link hopping. Having nothing better to do..

A simple venn diagram could solve this? Sample is 20. We have 2 subsets: squash and tennis. The intersection of the two groups is 5.

8 do not play squash, therefore the total within the squash subset must be 20-8= 12. Of the 12 who play squash, we know 5 play tennis also. Therefore those who play squash only must be 12-5= 7.

11 do not play tennis, therefore the total within the tennis subset must be 20-11=9. Of the 9 who play tennis, we know 5 play tennis also. Therefore those who play tennis only must be 9-5=4.

Finally, the number of ppl who play neither tennis nor squash must be:
20-(7+4+5)=4

- answer is C

how entertaining. i procrastinate brilliantly. thank you for helping me

By: Tracey

Tracey — Mon, 30 Jul 2007 10:58:39 +0000

You know you shouldn’t listen to Marilyn when she says she’s too simple minded. That’s the girl whose Biology professor said she was amazingly awesome for getting 100% on all her exams. :P

I wonder if my Venn diagram counts as proper working out and stuff. You sound as pedantic as my math teacher, “You must show ALL working or you don’t get full marks!” ;)

By: Vera

Vera — Mon, 30 Jul 2007 10:25:30 +0000

Well I suck at these things, but I’ll try my best.

First of all I detract 5 from 20, because these played both sports. So we now have 15 people.
From these 15:
- 8 didn’t play squash => 7 played squash
- 11 didn’t play tennis => 4 played tennis

7+4 = 11 these played either squash or tennis.

15 - 11 = 4 the people who didn’t play either.

So the correct answer would be C