请教一道prep的数学题目，百思不解！！！

everdeneli

On a certain tour bus, the ratio of the number of women and the number of childern is 5:2, what is the number of men?

(1) Children: men = 5:11

(2) women less than 30

(c) is correct, why?

notidgen

人的个数是整数

everdeneli

可是似乎只能求出men的范围，不能得到确切的number

是否我理解有问题

能不能给出详解

谢谢

sccrrc

2楼说的很精辟。我来详细叙述一下,assume:women 5a,children 2a

由条件一：men:22a/5

再加上条件二：a<6

那么，只有当a=5的时候，men的人数才能是整数22人。其他a的取值1,2,3,4虽然在小于6的范围内，但得不出整数的人数。

萍踪侠影

W/C=5/2 and C/M=5/11,so C must be multiple of 5x2, i.e. C is 10,or 20...

If C is 10, then W=25, M=22

If C is 20 or more, then W=50, M=44, but according to (2), W is less than 30,

So, C is 10 only.

Both (1) and (2) together are correct.

geniuswu06

Women：Children=5：2

Children：Men=5：11

W：M：C=25：10：22

25X<30 Hence,X=1 since X is integer.

In number，women=25，Children=10，Men=22. Total Number is 57.Therefore,C is the correct answer.

everdeneli

都好厉害

我真是笨死了

谢谢