Carcass wrote:
For which of the following values of n is (100+n)n NOT an integer?
(A) 1
(B) 2
(C) 3
(D) 4
(E) 5
The GRE loves this nice identity:
a+bc=ac+bcSo,
100+nn=100n+nn=
100n+1Since 1 is already an integer, we can see that 100/n + 1 will be an integer whenever 100/n is an integer.
In other words, 100/n + 1 is an integer whenever 100 is divisible by n.
Conversely, 100/n + 1 is NOT an integer whenever 100 is NOT divisible by n.
Since 100 is NOT divisible by 3, the correct answer is C