Problem Solving

kwah wrote:I have attached a question from GMAT Prep Test 1.

What is the most efficient way to achieve this result?

Answer:D

Please advise, thank you.
K

Let us assume that n = 5k for any integer k.
n = p²q, where p and q are primes.

Either p or q is 5, and we have to find which answer choice is a multiple of 25, so the correct answer should have both.
The power of p and q should be 2 or higher than that to be multiple of 25. Among the given answer choices only D is such choice.

The correct answer is D.