prep 中几道搞不清的题目 2

helenlife

On a certain sight seeing tour, the ratio of the women to the number of children was 5 to 2.
What was the number of men on the sight-seeing tour ?

A. On the sight-seeing tour, the ratio of the number of children to the number of men was 5 to 11
B. The number of women on the sight seeing tour was less than 30

Answer: C

I marked it as E. can someone please explain. thanks !!

avalon9527

题目可以得出W:C=5:2 (W,M,C均为整数)
1)C:M=5:11
2)W<30

条件1可以得出 W:C:M=25:10:22
条件2说W<30
条件1,2联立后，由于W,C,M都必须为整数，所以当W<30时，W只能为25.由此可以确定C=10，M=22