You are given a math word problem and you are supposed to make use of mathematical concepts like probability, combinatorics, linear equations, sequences/series, or simple operators like addition, subtraction, division, or multiplication to answer the given question. Choose the best option from the 5 given options and report that option.

[EX Q]: Question: If W is an integer greater than 6, which of the following must be divisible by 3?

 Option A: W(W+1

 Option B: N(N+2

 Option C: N(N+3

 Option D: N(N+4

 Option E: N(N+5
[EX A]: Option A

[EX Q]: Question: What is the sum of all the numbers which divides 100 ?

 Option A: 408

 Option B: 102

 Option C: 816

 Option D: 916

 Option E: 416
[EX A]: Option A

[EX Q]: Question: A boat travels 72 km downstream in 8 hours and 84 km upstream in 12 hours. Find the speed of the boat in still water and the speed of the water current ?

 Option A: 6 and 1 kmph

 Option B: 8 and 2 kmph

 Option C: 8 and 1 kmph

 Option D: 9 and 1 kmph

 Option E: 2 and 1 kmph
[EX A]:
Option C