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 is faster than B. A and B each walk 24 km. The sum of their speeds is 7 km/hr and the sum of times taken by them is 14 hours. Then, A's speed is equal to?

 Option A: 2 km/hr

 Option B: 3 km/hr

 Option C: 4 km/hr

 Option D: 7 km/hr

 Option E: 8 km/hr
[A]: Option B


[Q]: 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
[A]: Option C


[Q]: Question: If 25% of x is 15 less than 15% of 1500, then x is?

 Option A: 872

 Option B: 738

 Option C: 837

 Option D: 840

 Option E: 83
[A]:
Option D