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: If one-third of one-fourth of a number is 15, then three-tenth of that number is

 Option A: 35

 Option B: 36

 Option C: 45

 Option D: 54

 Option E: 57
[EX A]: Option D

[EX Q]: Question: A and B complete a work in 6 days. A alone can do it in 10 days. If both together can do the work in how many days?

 Option A: 3.75

 Option B: 3.76

 Option C: 3.79

 Option D: 3.74

 Option E: 3.71
[EX A]: Option A

[EX Q]: Question: A person purchased a TV set for Rs. 16000 and a DVD player for Rs. 6250. He sold both the items together for Rs. 31150. What percentage of profit did he make?

 Option A: 40

 Option B: 88

 Option C: 26

 Option D: 18

 Option E: 11
[EX A]:
Option A