TASK DEFINITION: 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.
PROBLEM: 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

SOLUTION: Option D

PROBLEM: Question: An article is bought for Rs.675 and sold for Rs.1215, find the gain percent?

 Option A: 33 1/9%

 Option B: 33 8/3%

 Option C: 33 1/3%

 Option D: 33 2/3%

 Option E: 80%

SOLUTION: Option E

PROBLEM: Question: Five different books (A, B, C, D and E) are to be arranged on a shelf. Books C,D and E are to be arranged first and second starting from the right of the shelf. The number of different orders in which books A, B and may be arranged is

 Option A: 1!

 Option B: 2!

 Option C: 5!

 Option D: 15!

 Option E: 24!

SOLUTION:
Option B