Given a math problem with context and a question and 5 answer choices, the task is to provide the correct answer choice based on the problem. You must choose one of the given answer choices by letter: a, b, c, d, or e; anything else is invalid.

[Q]: Problem: the average score of a cricketer in 2 matches is 30 and in other 3 matches is 40. then find the average score in all the 5 matches ?
Options: a. 25, b. 27, c. 30, d. 35, e. 36
[A]: e

[Q]: Problem: 54671 - 14456 - 31466 = ?
Options: a. 2449, b. 5449, c. 8749, d. 8449, e. 6468
[A]: c

[Q]: Problem: a metered rikshaw charges rs 13.50 for the first 1 km and 2.50 per 1 / 3 km there after. what would the charge if this rikshaw is hired for 13 kms ? in approx ? ?
Options: a. 103.5 rs, b. 104.5 rs, c. 105.5 rs, d. 106.5 rs, e. 107.5 rs
[A]:
a