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 certain number of workers can do a work in 85 days. If there were 10 workers more it could be finished in 10 days less. How many workers are there?

 Option A: 75

 Option B: 30

 Option C: 28

 Option D: 24

 Option E: 32
[A]: Option A


[Q]: Question: The average weight of 10 person's increases by 4 kg when a new person comes in place of one of them weighing 70kg. What is the weight of the new person?

 Option A: 85

 Option B: 86.5

 Option C: 90

 Option D: 88.5

 Option E: 110
[A]: Option E


[Q]: Question: A train 540 meters long is running with a speed of 54 kmph. The time taken by it to cross a tunnel 180 meters long is?

 Option A: 29

 Option B: 18

 Option C: 48

 Option D: 99

 Option E: 11
[A]:
Option C