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: ages of two persons differ by 20 years. if 6 year ago, the elder one be 3 times as old the younger one, find their present age
Options: a. 12,28, b. 14,30, c. 16,36, d. 18,34, e. 19,34

Answer: c


Question: Problem: the speed of the boat in still water in 12 kmph. it can travel downstream through 48 kms in 3 hrs. in what time would it cover the same distance upstream ?
Options: a. 8 hours, b. 6 hours, c. 4 hours, d. 5 hours, e. 6 hours

Answer: e


Question: Problem: a train passes a platform in 32 seconds. the same train passes a man standing on the platform in 20 seconds. if the speed of the train is 54 km / hr, the length of the platform is
Options: a. 180 meter, b. 240 meter, c. 200 meter, d. 260 meter, e. none of these

Answer:
a