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: The average runs scored by a batsman in 20 matches is 40. In the next 10 matches the batsman scored an average of 20 runs. Find his average in all the 30 matches?

 Option A: 31

 Option B: 46

 Option C: 88

 Option D: 33.33

 Option E: 12
[EX A]: Option D

[EX Q]: Question: A cycle is bought for Rs.900 and sold for Rs.1150, find the gain percent?

 Option A: 15

 Option B: 20

 Option C: 27.77

 Option D: 40

 Option E: 12
[EX A]: Option C

[EX Q]: Question: A train passes a station platform in 36 seconds and a man standing on the platform in 20 seconds. If the speed of the train is 54 km/hr, what is the length of the platform?

 Option A: 120 m

 Option B: 240 m

 Option C: 300 m

 Option D: 360 m

 Option E: 280 m
[EX A]:
Option B