GMAT Question:
If b ≠ 0 and a > b, is a > c?
(1) a/b> c/b
(2) 5ab > 6bc
From a cursory glance, you can see that GMAT math takes you back to concepts that you learned in high school. Look a bit closer and you see that it actually takes you back much further than that, to math you learned in elementary school - integers, positives/negatives, etc. One of the interesting things about the GMAT is that sometimes these throwbacks to simple math are used to create challenging critical thinking problems. The problem above is one of those.
Post your answer and your method in the comments below. We'll share the full Kaplan explanation, with secrets for how to master GMAT Data Sufficiency, in tomorrow's blog entry.
If b ≠ 0 then b > 0 (positive) or b c/b. Lets say b = 1 then a > c. Now lets say b = -1, then -a > -c. Multiply by -1. a 6bc.
Lets say b = 1, then 5a > 6c. 5(1/5)a > 6(1/5)c . a > 1.2c so a > c.
Now lets say b = -1 , then -5a > -6c. Multiply by -1 5a < 6c. a c or a < c. Insufficient.
Answer is E.