Yes, you need to refresh or build your maths knowledge to be able to solve GMAT questions in the Quantitative and the Integrated Reasoning sections of the exam.

 

This short GMATPrepNow video provides a detailed explanation on how to solve questions related to Integer Properties. Doesn't ring a bell? No worries. Just watch the video.

Here is the question and part of the solution. Find all details in the video.

GMAT Math Even/Odd Questions (Video) PrepAdviser