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 man rows his boat 85 km downstream and 45 km upstream, taking 2 1/2 hours each time. Find the speed of the stream?

 Option A: 6 kmph

 Option B: 9 kmph

 Option C: 3 kmph

 Option D: 8 kmph

 Option E: 1 kmph
[EX A]: Option D

[EX Q]: Question: A bike covers a certain distance at the speed of 67km/h in 8 hrs. If the bike was to cover the same distance in approximately 6 hrs, at what approximate speed should the bike travel?

 Option A: 89.33 km/h

 Option B: 85.34 km/h

 Option C: 87.67 km/h

 Option D: 90.25 km/h

 Option E: 90.64 km/h
[EX A]: Option A

[EX Q]: Question: George went to a fruit market with certain amount of money. With this money he can buy either 50 oranges or 40 mangoes. He retains 8% of the money for taxi fare and buys 20 mangoes. How many oranges can he buy?

 Option A: 21

 Option B: 30

 Option C: 20

 Option D: 16

 Option E: 12
[EX A]:
Option A