GMAT Prep Ratio Question - Very puzzled

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GMAT Prep Ratio Question - Very puzzled

by ssy » Sat Oct 20, 2007 10:27 pm
Here's a question from one of the GMAT prep practice tests. Could someone kindly explain the answer?

On a certain sightseeing tour, the ratio of the number of women to the number of men is 5 to 2. What is the number of men on the tour?

1) The ratio of the number of men to the number of children is 5 to 11.

2) The number of women on the tour is less than 30.


The answer is C, both statements together are sufficient.

I thought it was E, none of the statements are sufficient as statement #2 does not even specifiy a unique value for the number of women. Please help, thanks!

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by jangojess » Sat Oct 20, 2007 10:36 pm
stmt 1 - m:c = 5:11 but from the Q we can get that w:m = 5:2. now taking the ratio of all the three we get that w:m:c = 25:10:22...This is still a ratio and so we can't get the number of men...So insuff

stmt 2 - w < 30 and w:m = 5:2 but number of women can be any multiple of 5 less than 30...so insuff

both - we know that w:m:c = 25:10:22 and w<30...so w must be 25 which means that m=10 and c=22...So suff.....Ans is C
Trying hard!!!

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by ssy » Sat Oct 20, 2007 10:53 pm
Thank you for your quick response JangoJess!

That is what I thought as well but I took it to a friend of mine who's really good at math who said it was still insufficient.

Is it right to say that given that the ratio of w:m:c is 25:10:22, the number of woman can only be 25 because if it is any other multiple of 5 -20, 15, 10..etc, the number will not satisfy the entire ratio?

I.e. If we take the number of women to be 15, the number of men and children will not be an integer.

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by jangojess » Sat Oct 20, 2007 11:02 pm
u got it right ssy..........
Trying hard!!!