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: if the radius of a cylinder is made 3 times and so is the height, what is the new volume of the cylinder divided by the old one ?
Options: a. 27., b. 2., c. 6., d. 4., e. 10.
[A]: a


[Q]: Problem: mary works in a restaurant a maximum of 70 hours. for the first 20 hours, she is paid $ 8 per hour. for each overtime hour, she is paid at a rate which is 25 % higher than her regular rate. how much mary can earn in a week ?
Options: a. 600, b. 620, c. 660, d. 320, e. 400
[A]: c


[Q]: Problem: 33 1 / 3 % of 36 ?
Options: a. 16, b. 21, c. 18, d. 12 number, e. 18
[A]:
d