If W is an integer greater than 6, which of the following must be divisible by 3? Choices
A) W(W+1)(W-4) B) N(N+2)(N-1) C) N(N+3)(N-5) D) N(N+4)(N-2) E) N(N+5)(N-6)
Now take W = 3k , W = 3k+1 W = 3k+2..put in all the choices. If by putting all the values of W we get it is divisible by 3, then it is correct answer choice.   A is correct. It will hardy take 10 sec per choice as we have to consider only 3k+1 and 3k+2.
<result>A</result>
If W is an integer greater than 6, which of the following must be divisible by 3?