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.

Example Input: Question: A cycle is bought for Rs.900 and sold for Rs.1150, find the gain percent?

 Option A: 15

 Option B: 20

 Option C: 27.77

 Option D: 40

 Option E: 12
Example Output: Option C

Example Input: Question: A man can row a boat at 20 kmph in still water. If the speed of the stream is 6 kmph, what is the time taken to row a distance of 66 km downstream?

 Option A: 30/83 hours

 Option B: 33/13 hours

 Option C: 31/13 hours

 Option D: 30/13 hours

 Option E: 30/14 hours
Example Output: Option B

Example Input: Question: subash can copy 50 pages in 10 hrs.subash and prakash together can copy 300 pages in 40 hours.in how much time prakash can copy 10 pages.

 Option A: 8

 Option B: 10

 Option C: 12

 Option D: 4

 Option E: 16
Example Output:
Option D