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.

Q: Question: A man’s speed with the current is 18 km/hr and the speed of the current is 2.5 km/hr. the man’s speed against the current is :

 Option A: 8.5 km/hr

 Option B: 9.5 km/hr

 Option C: 13 km/hr

 Option D: 12.5 km/hr

 Option E: None of these

A: Option C
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Q: Question: P can do a work in 24 days. Q can do the samework in 9 days & R can do the same work in 12 days. Q & R start the work and leave after 3 days. P finishes the remaining work in how many days.

 Option A: 8

 Option B: 10

 Option C: 14

 Option D: 16

 Option E: 19

A: Option B
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Q: Question: A fill pipe can fill 1/2 of cistern in 20 minutes. In how many minutes, it can fill 1/2 of the cistern?

 Option A: 5min

 Option B: 10min

 Option C: 15min

 Option D: 20min

 Option E: 25min

A:
Option D
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