1 2 3 4 5 6 7 8 9 10 11 12lightbulb wrote: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 3
OA: C
1) 1, 3, 5, 7, 9, 11 ; (N-1)(N+1) is divided by 24 gives us different R
2) 1,2,4,5,7,8,10 ; (N-1)(N+1) is divided by 24 gives us different R
1+2 ) 1,5,7,11 ' (N-1)(N+1) is divided by 24 gives us 0 as the remainder
Hence, C
