• 7 CATs FREE!
If you earn 100 Forum Points

Engage in the Beat The GMAT forums to earn

### GMAT/MBA Expert

GMAT Instructor
Posts: 1031
Joined: 03 Jul 2008
Location: Malibu, CA
Thanked: 716 times
Followed by:255 members
GMAT Score:750
by Brian@VeritasPrep » Thu Aug 05, 2010 12:15 pm
Great thread, everyone! You've all worked the problem out nicely, but it also brings up a pretty key takeaway that's worth mentioning.

I talk to my students about "finding opportunities to do what you do well", kind of like the business concept of "core competencies" (if you're, like Amazon.com, great at distribution of media, then find opportunities like the Kindle to continue to do it even better; Amazon, however, isn't great at brick-and-mortar setups, so you won't see them partnering with Starbucks to create in-person stores with cafes, etc.).

On the GMAT, there are things that you should be good at, and some things that you can probably recognize right away that you're not good at (at least not in ~2 minutes per question without a calculator).

This is a great example of that - we're awful at adding and subtracting exponents, but we're pretty good at multiplying them. When you see a series of exponents added together, you probably need to find a way to use your "core competency" of multiplication. The easiest way to do that is typically to factor, which allows you to turn addition into multiplication.

When you see complex problems on the GMAT, ask yourself how to turn what you see into something that you do well. With core competencies like prime factorization, factoring, using number properties, etc., you should be able to solve any problem as long as you can get that problem on your terms.
Brian Galvin
GMAT Instructor