Help Needed !!
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The question asks:
Is 10^(-x) < 0.01 ?
We can rewrite the question so we have powers of 10 on both sides:
Is 10^(-x) < 1/100 ?
Is 10^(-x) < 10^(-2)
and for the answer to be yes, the power on the left side needs to be smaller than the power on the right side, so our question becomes
Is -x < -2 ?
Is x > 2?
So Statement 2 is not sufficient, but only on a silly technicality that you would never see on the real GMAT - Statement 2 leaves open the possibility that x is exactly equal to 2.
The typesetting in Statement 1 is a bit bizarre but I think it means to say:
10^(-x) + (6/25) < 1/4
which we can rewrite:
10^(-x) < 1/4 - 6/25
10^(-x) < 25/100 - 24/100
10^(-x) < 1/100
which is precisely what we wanted to prove. So Statement 1 is sufficient and the answer is A.
Is 10^(-x) < 0.01 ?
We can rewrite the question so we have powers of 10 on both sides:
Is 10^(-x) < 1/100 ?
Is 10^(-x) < 10^(-2)
and for the answer to be yes, the power on the left side needs to be smaller than the power on the right side, so our question becomes
Is -x < -2 ?
Is x > 2?
So Statement 2 is not sufficient, but only on a silly technicality that you would never see on the real GMAT - Statement 2 leaves open the possibility that x is exactly equal to 2.
The typesetting in Statement 1 is a bit bizarre but I think it means to say:
10^(-x) + (6/25) < 1/4
which we can rewrite:
10^(-x) < 1/4 - 6/25
10^(-x) < 25/100 - 24/100
10^(-x) < 1/100
which is precisely what we wanted to prove. So Statement 1 is sufficient and the answer is A.
For online GMAT math tutoring, or to buy my higher-level Quant books and problem sets, contact me at ianstewartgmat at gmail.com
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