sk88 wrote:

Ok, this one was in my

kaplan math workbook, but there must be a misprint in the answers, because the answer to this one was omitted...

S is a set of positive integers such that if integer x is a member of S, then both \(x^2\) and \(x^3\) are also in S. If the only member of S that is neither the square nor the cube of another member of S is called the source integer, is 8 in S?

(1) 4 is in S and is not the source integer

(2) 64 is in S and is not the source integer

I think the answer is E...what does everyone else think?

St1:

If 4 is in S and is not the source integer then 2 must be present in S => 2^3 = 8 must also be present in S.

=> SUFFICIENTSt2:

If 64 is in S and is not the source integer then it could either be due to 4 as a source integer or 2 as a source integer.

If 2 is the source integer then 8 is in S else its not.

=> NOT SUFFICIENTANS: A _________________

KUDOS me if I deserve it !!

My GMAT Debrief - 740 (Q50, V39) | My Test-Taking Strategies for GMAT | Sameer's SC Notes