Hey. Where is this question from plz? I only work with official questions (OGs, GMATPrep) because they make the best practice Qs for the real GMAT.

as far as i see the query
find w^1/3-?
(1)w^1/5=64
w=(2^6)^5=2^30
so w^1/3=(2^30)^1/3=2^10-sufficient

(2)w^15=4,w=(2^2)^15=2^30
(2^30)^1/3=2^10-sufficient
so D

it is better to sent this in DS section

if you need the cube root of W you are basically looking for the value of W, and then you would take the cube root.

statement 1 says the 5th root of W is 64 - becuase we know we can take 64^5 to get the value of W this answer is sufficient (don't have to actually solve it)

AD

Statement 2 is similar - it says that teh 15th root of W is 4 - again here we don't have to actually solve the problem, just know that we can - we can take 4^15 to find W and then find the cube root - becuase we know we can solve this the answer is D.

This is a good question to point out that most of the time on DS you are looking for concepts, not actual solutions.

tpr-becky wrote:if you need the cube root of W you are basically looking for the value of W, and then you would take the cube root.

statement 1 says the 5th root of W is 64 - becuase we know we can take 64^5 to get the value of W this answer is sufficient (don't have to actually solve it)

AD

Statement 2 is similar - it says that teh 15th root of W is 4 - again here we don't have to actually solve the problem, just know that we can - we can take 4^15 to find W and then find the cube root - becuase we know we can solve this the answer is D.

This is a good question to point out that most of the time on DS you are looking for concepts, not actual solutions.

Thanks! often i get lost in solving ds questions, will actively try to stop the need to do so from now on...otherwise, the problem is quite easy. thanks!


@ Patrick_GMATFix - this question is part of a set of mock gmat exams from a gmat prep centre. i've been told it contains real gmat questions.