vinayreguri wrote:If x, y & Z are digits of the three digit + ve integer N, what is the reminder when N is divided by 3
1. x+y+z=11
2. N=2 is divisible by 3
[spoiler]OA: D[/spoiler]
There's a rule of divisibility that says that a if the sum of the digits of a number is divisible by 3, then the number itself is divisible by 3.
(1) is an extension of the same: if the sum of the digits of a number is 11, then that number is 2 more than another number whose sum of digits is 9, which is divisible by 3. Therefore, N is 2 more than some multiple of 3, which means that the remainder when N is divide by 3 is 2. Sufficient.
(2) I assume that the statemnt actually says N-2 is divisible by 3, which is basically saying the same thing as stat. (1): N leaves a remainder of 2 when divided by 3.
