[GMAT math practice question]
If 0.00012345 is between 1/10^n and 1/10^{n-1}, what is the value of n?
A. 2
B. 3
C. 4
D. 5
E. 6
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If 0.00012345 is between 1/10^n and 1/10^{n-1}, what is the
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Max@Math Revolution
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We need to examine powers of 10 that are smaller than AND greater than 0.00012345Max@Math Revolution wrote:[GMAT math practice question]
If 0.00012345 is between 1/10^n and 1/10^{n-1}, what is the value of n?
A. 2
B. 3
C. 4
D. 5
E. 6
We know that: 0.0001 < 0.00012345 < 0.001
Rewrite as FRACTIONS to get: 1/10,000 < 0.00012345 < 1/1,000
Rewrite as POWERS OF 10 to get: 1/10� < 0.00012345 < 1/10³
We're told that 0.00012345 is between 1/10^n and 1/10^{n-1}
So, we can now see that n = 4
Answer: C
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Max@Math Revolution
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=>
0.0001 < 0.00012345 < 0.001
10^{-4} < 0.00012345 < 10^{-3}
1/10^4 < 0.00012345 < 1/10^3
Comparing this with 1/10^n < 0.00012345 < 1/10^{n-1} yields n = 4.
Therefore, the answer is C.
Answer: C
0.0001 < 0.00012345 < 0.001
10^{-4} < 0.00012345 < 10^{-3}
1/10^4 < 0.00012345 < 1/10^3
Comparing this with 1/10^n < 0.00012345 < 1/10^{n-1} yields n = 4.
Therefore, the answer is C.
Answer: C
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