Re: The arithmetic mean (average) of the numbers a and b is 17.
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13 Apr 2019, 03:09
I don't think geometric mean will be on the GRE. So that's a clue to not even try to calculate it or use algebra here.
We are not told anything at all about a and b. They could be positive or negative, integers or not. We're only given means of a and b, but no information at all about which one is bigger. So it's impossible for one to be bigger. If it could be true that a = 9 and b = 7, then it could also be true that a = 7 and b = 9.
There is a chance that they are equal. But checking that would require some knowledge of geometric mean, which the test won't require. So we can safely assume that D is the answer.