L, M, N and O are four mothers each of whom has two daughter

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L, M, N and O are four mothers each of whom has two daughters. Peter wants to find out the
ages of each of the daughters of all the four mothers. However when he asks the mothers the
ages of their children the following is the response she receives
(i) L says when you multiply my daughters ages the answer is 9 and the youngest one was born
in January
(ii) M says when you add the ages of both my daughters and square the answer is 169 .The age
of my older daughter is a perfect cube
(iii)N says that the when you multiply the ages of her daughters the answer is 77. N's own age is
32 years
(iv) O says that upon adding the ages of her daughters the result is a two digit number XY. Upon
multiplying the ages of her daughters the result is a two digit number YX. The ages of both
her daughters are under 10 years
For how many of the mothers can Pater be absolutely sure of the ages of both daughters?

A) I & II

B) I , III, IV

C) II, III

D) IV

E)I,II, III, IV

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by Brent@GMATPrepNow » Mon Jun 08, 2015 5:55 am
In my opinion, this question is too long for the GMAT.
Plus it's somewhat ambiguous.
GOAL: Peter wants to find out the ages of each of the daughters of all the four mothers.
Let's say I have 2 daughters (Ann and Bea), and the product of their ages is 5.
If we stick with integer values, then the ages are 1 and 5. However, is Ann 1 years old, or is Bea 1 years old? The answer choices suggest that I would have enough information even though I don't know the age of each daughter.

Plus the question uses information (e.g, "the youngest one was born in January") that's similar to a well-known math riddle: https://mathforum.org/library/drmath/view/58492.html

That said, the question is solvable. It's just too time-consuming (and ambiguous).

What's the source?

Cheers,
Brent
Brent Hanneson - Creator of GMATPrepNow.com
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