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.

[EX Q]: Question: A fish can go upstream at 35 kmph and downstream at 55 kmph, and then find the speed of the fish in still water?

 Option A: 45

 Option B: 55

 Option C: 35

 Option D: 65

 Option E: 70
[EX A]: Option A

[EX Q]: Question: 5 men are equal to as many women as are equal to 8 boys. All of them earn Rs.210 only. Menâ€™s wages are?

 Option A: 6Rs

 Option B: 2Rs

 Option C: 4Rs

 Option D: 9Rs

 Option E: 14Rs
[EX A]: Option E

[EX Q]: Question: Sandy can do a job in 15 days and Molly can do the same job in 30 days. If they work together, in how many days will they complete the job?

 Option A: 8

 Option B: 9

 Option C: 10

 Option D: 11

 Option E: 12
[EX A]:
Option C