This week, we’re going to talk about what to know for consecutive integer problems and how to recognize what to do on future problems of the same type.

This one is from GMATPrep. Set your timer for 2 minutes. and GO!

*  If n is a positive integer and r is the remainder when n² “ 1 is divided by 8, what is the value of r?

 

(1) n is odd.

(2) n is not divisible by 8.

The first thing you’ll probably notice: I didn’t include the answer choices. The five Data Sufficiency answer choices are always the same, so we should have those memorized. If you don’t have them memorized yet, add this to your to do list.

Just in case, here are the five choices (in casual language, not official language):

(A) statement 1 works but statement 2 does not work

(B) statement 2 works but statement 1 does not work

(C) the statements do NOT work alone, but they DO work together

(D) each statement works by itself

(E) nothing works, not even using them together

Okay, now that we’ve got that out of the way, let’s tackle this problem! This one’s a theory question; they’re asking us about the concept of consecutive integers (as opposed to asking us to do more straightforward calculations with consecutive integers) and they’re not even nice enough to tell us straight out that this is about consecutive integers! We have to figure that out or “ even better “ recognize it.

Read more