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: Two pipes A and B can fill a cistern in 20 and 30 minutes respectively, and a third pipe C can empty it in 40 minutes. How long will it take to fill the cistern if all the three are opened at the same time?

 Option A: 17 1/5

 Option B: 17 1/8

 Option C: 17 1/7

 Option D: 17 1/1

 Option E: 17 1/2
Example Output: Option C

Example Input: Question: a light flashes every 30 seconds, how many times will it flash in ? of an hour?

 Option A: 550

 Option B: 600

 Option C: 650

 Option D: 700

 Option E: 120
Example Output: Option E

Example Input: Question: If the cost price of 15 articles is same as the selling price of 25 articles. Find the gain or loss percentage?

 Option A: 30% Gain

 Option B: 30% Loss

 Option C: 40% Gain

 Option D: 40% Loss

 Option E: 50% Loss
Example Output:
Option D