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.
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Question: Question: Running at the same constant rate, 8 identical machines can produce a total of 240 pens per minute. At this rate, how many pens could 5 such machines produce in 5 minutes?

Option A: 114

Option B: 108

Option C: 192

Option D: 750

Option E: 777

Answer: Option D

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: In an election between two candidates, 10% of votes are were declares invalid. First candidate got 3600 votes which were 60% of the total valid votes . The total number of votes enrolled in that election was:

Option A: 9000

Option B: 98000

Option C: 20000

Option D: 11000

Option E: 12000

Answer:
Option C