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: Two pipes A and B can separately fill a cistern in 10 and 15 minutes respectively. A person opens both the pipes together when the cistern should have been was full he finds the waste pipe open. He then closes the waste pipe and in another 4 minutes the cistern was full. In what time can the waste pipe empty the cistern when fill?

 Option A: 7

 Option B: 9

 Option C: 5

 Option D: 4

 Option E: 8
answer:
Option E


question:
Question: Rs.8000 become Rs.11256 in a certain interval of time at the rate of 5% per annum of C.I. Find the time?

 Option A: 6 YEARS

 Option B: 7

 Option C: 5

 Option D: 3

 Option E: 4
answer:
Option B


question:
Question: John has 10 pairs of matched socks. If he loses 3 individual socks, what is the greatest number of pairs of matched socks he can have left?

 Option A:  7

 Option B:  8

 Option C:  5

 Option D:  4

 Option E:  3
answer:

Option B