Wrong place. This thread should be in the Data Sufficiency sub-forum.
I don't have OG12 handy with me, so if you don't mind posting the problem here, I can help you out.
Thanks!
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Source: Beat The GMAT — Data Sufficiency |
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beatthegmatinsept
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Sorry for posting in the wrong place (just started here). But thank you in advance for helping! Here's the problem: If n is a positive integer, is (1/10)^n <0.01?
(1) n>2
(2) (1/10)^n-1 < 0.1
I thought only A would be sufficient. But turns out either statement is.
(1) n>2
(2) (1/10)^n-1 < 0.1
I thought only A would be sufficient. But turns out either statement is.
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InkyBinky
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Yeah, next time put it in the math section, but I'll answer it here.Cookee Belen wrote:Sorry for posting in the wrong place (just started here). But thank you in advance for helping! Here's the problem: If n is a positive integer, is (1/10)^n <0.01?
(1) n>2
(2) (1/10)^n-1 < 0.1
I thought only A would be sufficient. But turns out either statement is.
Per my response to your general question on DS, put the given equation into a more useful form:
(1/10)^n = 10^-n
0.01 = 10^-2
So...
10^-n < 10^-2
Solving for n, the question is really asking: Is n > 2?
Knowing this, part 1 is obviously sufficient. Now look at part 2 and manipulate:
(1/10)^(n-1) < 10^-1
(1/10)^(n-1) = [(1/10)^n] * (1/10)^-1 = (10^-n) * 10
Dividing each side by 10, you get:
10^-n < 10^-2
This is a restatement of the second to last step in the original problem's manipulation above, so it answers the question and is sufficient.
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anantbhatia
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(1) itself is sufficient
(2) is (1/10)^n-1<0.1
so (1/10)^n<0.01 ie. LHS < RHS. That's what we wanted to know... Hence (2) being an assertion, answers the question if LHS was actually < RHS.
Is that understanding correct?
(2) is (1/10)^n-1<0.1
so (1/10)^n<0.01 ie. LHS < RHS. That's what we wanted to know... Hence (2) being an assertion, answers the question if LHS was actually < RHS.
Is that understanding correct?
