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.

Question: A man rows his boat 85 km downstream and 45 km upstream, taking 2 1/2 hours each time. Find the speed of the stream?

Option A: 6 kmph

Option B: 9 kmph

Option C: 3 kmph

Option D: 8 kmph

Option E: 1 kmph
Option D

Question: X is a prime number bigger than 10. Also, Y = X+X^3+X^5+X^7. What is definitely true about Y?

Option A: Y is a prime number.

Option B: Y is odd.

Option C: Y is even.

Option D: Y is divisible by 3.

Option E: Y is divisible by 7.
Option C

Question: There are 8 red, 7 blue and 6 green balls, 1 ball is picked up randomly thenwhat is the probability that neither blue nor green?

Option A: 2/21

Option B: 1/21

Option C: 3/25

Option D: 3/29

Option E: 8/21
Option E