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: P alone can complete a piece of work in 14 days. Work done by Q alone in one day is equal to one-third of the work done by P alone in one day. In how many days can the work be completed if P and Q work together?

 Option A: 6 (1/4

 Option B: 21/2 days

 Option C: 7 (3/4

 Option D: 8/5 days

 Option E: 9 (3/4
[A]: Option B


[Q]: Question: A train sets off at 2 p.m. at the speed of 70 kmph. Another train starts at 3:30 p.m. in the same direction at the rate of 85 kmph. At what time the trains will meet?

 Option A: 10.36

 Option B: 10.39

 Option C: 10.3

 Option D: 10.34

 Option E: 10.31
[A]: Option C


[Q]: Question: Find the annual income derived by investing $ 6800 in 30% stock at 136.

 Option A: 550

 Option B: 1500

 Option C: 250

 Option D: 1300

 Option E: 400
[A]:
Option B