instruction:
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:
Question: A cistern can be filled by a tap in 3 hours while it can be emptied by another tap in 9 hours. If both the taps are opened simultaneously, then after how much time will the cistern get filled?

 Option A: 2.9 hrs

 Option B: 4.5 hrs

 Option C: 2.9 hrs

 Option D: 7.2 hrs

 Option E: 8.6 hrs
answer:
Option B


question:
Question: If the average (arithmetic mean) of x, x + 2, and x + 4 is 33, what is the value of x?

 Option A: 30

 Option B: 31

 Option C: 32

 Option D: 32

 Option E: 37
answer:
Option B


question:
Question: Two trains running in opposite directions cross a man standing on the platform in 27 seconds and 17 seconds respectively and they cross each other in 24 seconds. The ratio of their speeds is?

 Option A: 3/7

 Option B: 3/2

 Option C: 3/5

 Option D: 3/1

 Option E: 7/3
answer:

Option E