2^x greater than 100?

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by Arcane66 » Fri May 06, 2011 6:23 pm
The first thing I did was write out what the problem is asking. I wrote, "Is 2^x > 100?" Then, I solved for x for the first data piece. If you know how to solve it, you should get x=16. 2^16 is definitely greater than 100, so the answer is either A or D. Looking at the second piece, I rewrote it on a piece of paper and solved to get 50 < x. Another way of saying this is x is greater than 50. Clearly if x is greater than 50, then 2^x is greater than 100. So, both can be used to figure out the answer. So you select D.

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by Anurag@Gurome » Fri May 06, 2011 7:50 pm
tonebeeze wrote:Is 2^x greater than 100??

1. 2√x = 8

2. [1/(2^x)] < 0.01

OA = D
(1) 2√x = 8 or √x = 4 or x = 4² = 16
So, 2^16 > 100.
Hence, (1) is SUFFICIENT to answer the question.

(2) [1/(2^x)] < 1/100 implies 2^x > 100
Hence, (2) is SUFFICIENT to answer the question.

The correct answer is D.
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