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: The time taken by a man to row his boat upstream is twice the time taken by him to row the same distance downstream. If the speed of the boat in still water is 42 kmph, find the speed of the stream?

 Option A: 12

 Option B: 15

 Option C: 14

 Option D: 18

 Option E: 19

SOLUTION: Option C

PROBLEM: Question: If x and y are negative integers, which of the following statements must be true?
I. (-x)^y is positive.
II. (-x)^(-y) is positive.
III. x^(-y) is positive.

 Option A: None

 Option B: II only

 Option C: I and II

 Option D: I and III

 Option E: I, II and III

SOLUTION: Option C

PROBLEM: Question: What is the difference between the C.I. on Rs. 8000 for 1 1/2 years at 4% per annum compounded yearly and half-yearly?

 Option A: s.3.26

 Option B: s.2.08

 Option C: s.2.02

 Option D: s.2.83

 Option E: s.2.42

SOLUTION:
Option A