For today's GMAT Question of the Day, we have an AD/BCE Value Question, relating to question #311 from the Official Guide for GMAT Review, 2017. See below for a clear, step-by-step example and explanation.

We need to find:

Obviously, we need information about Guy’s gross income and his deductions. Because you’ve already scanned the clues (right?), you know that this is a CE question – clue (1) only mentions gross income, and clue (2) only mentions deductions. So, eliminate A, D, and B

(1) and (2) Let’s try some examples, and let’s use multiples of \$100 to keep calculations simple:

Note that I only changed the deductions and I didn’t actually calculate the percent change for each example. It’s plain to see that they are not equal.

Takeaways:

1. Be on the lookout for CE problems (see 246 and 255 for examples of easy CE problems).
2. Don’t create more examples than you need. In this case we only changed the deductions.
3. Use multiples of \$100 in percent problems that don’t include actual value
4. Don’t calculate unless you have to!

John is a Senior MyGuru GMAT tutor based in Chicago, but is also the founder of Owl Test Prep . We encourage you to check out their web-site and YouTube channel.

Topics: GMAT quant, GMAT prep