Needgmat wrote:If n is a positive integer, what is the ten digit of n?
1) The hundreds digit of 10n is 6
2) The tens digit of n+1 is 7
Statement 1:
10n = 600, 610, 620, 630...
If we divide both sides by 10, we get the following options for n:
n = 60, 61, 62, 63...
In every case, the tens digit of n is 6.
SUFFICIENT.
Statement 2:
n+1 = 70, 71, 72...
If we subtract 1 from both sides, we get the following options for n:
n = 69, 70, 71...
If n=69, then its tens digit is 6.
If n=70, then its tens digit is 7.
Since the tens digit can be different values, INSUFFICIENT.
The correct answer is
A.
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