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: 50 % of a number is more than 40 % of 120 by 180. find the number ?
Options: a. 456, b. 480, c. 420, d. 445, e. 320

A: a
****
Q: Problem: how many prime numbers are between 29 / 3 and 87 / 6 ?
Options: a. 1, b. 2, c. 3, d. 4, e. 5

A: b
****
Q: Problem: the average weight of 16 boys in a class is 50.25 kg and that of the remaining 8 boys is 45.15 kg. find the average weights of all the boys in the class.
Options: a. 47.55 kg, b. 48 kg, c. 48.55 kg, d. 49.25 kg, e. 59.25 kg

A:
c
****