source - GMATPrep
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If n is a positive integer and r is the remainder when (n-1)(n+1) is divided by 24, what is the value of r ?
1) n is not divisible by 2
2) n is not divisible by 4
see answer below -
Ans = C.
I have no idea how to do this - any help ?
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If n is a positive integer and r is the remainder when (n-1)(n+1) is divided by 24, what is the value of r ?
1) n is not divisible by 2
2) n is not divisible by 4
see answer below -
Ans = C.
I have no idea how to do this - any help ?
