If ab=1, what is the value of (axb) (ayb) ?
source is manhattan review
any one please explain the answer, thanks in advance..
Given: \(ab=1\). Question: \((axb)*(ayb)=?\)
(1) ax=by=2, so \(ax=2\) and \(by=2\) --> \((axb)*(ayb)=(ax)*(by)*(ab)=2*2*1=4\). Sufficient.
(2) 2xy=4, so \(xy=2\) --> \((axb)*(ayb)=(ab)*(ab)*(xy)=1*1*2=2\). Sufficient.
Now, technically answer should be D, as EACH statement ALONE is sufficient to answer the question
But even though formal answer to the question is D (EACH statement ALONE is sufficient), this is not a realistic GMAT question, as: on the GMAT, two data sufficiency statements always provide TRUE information and these statements never contradict each other
So we can not have answer 4 from statement (1) and answer 2 from statement (2), as in this case statements would contradict each other.
I guess statement (2) should read xy=4 instead of 2xy=4, in this case answer will be D and the statements won't contradict each other.
Hope it's clear.
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