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.
--------
Question: Problem: excluding the stoppages, the speed of a bus is 48 km / hr and including the stoppages the speed of the bus is 12 km / hr. for how many minutes does the bus stop per hour ?
Options: a. 45 min, b. 10 min, c. 12 min, d. 20 min, e. 18 min

Answer: a


Question: Problem: in n is a positive integer less than 200, and 14 n / 60 is an integer, then n has how many different positive prime factors s ?
Options: a. 2, b. 3, c. 5, d. 6, e. 8

Answer: b


Question: Problem: a can do a work in 15 days b in 14 days and c in 16 days. if they work on it together then in how many days required to complete the work ?
Options: a. 3360 / 210, b. 3360 / 21, c. 3360 / 674, d. 3360 / 240, e. 3360 / 224

Answer:
c