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: jack has two dice, one has 6 equally probable sides, labeled 1, 2, 3, 4, 5, 6, and the other has 7 equally probable sides, labeled 1, 2, 3, 4, 5, 6, 7. if jack rolls both dice what is the probability that both of the number ' s sum will be 13 ?
Options: a. 3 / 14, b. 2 / 7, c. 1 / 3, d. 1 / 42, e. 12 / 21
[A]: d


[Q]: Problem: water is leaking out from a cylinder container at the rate of 0.31 m ^ 3 per minute. after 10 minutes, the water level decreases 1 / 9 meters. what is value of the radius in meters ?
Options: a. 2, b. 3, c. 4, d. 6, e. 9
[A]: b


[Q]: Problem: cole drove from home to work at an average speed of 80 kmh. he then returned home at an average speed of 120 kmh. if the round trip took a total of 2 hours, how many minutes did it take cole to drive to work ?
Options: a. 66, b. 70, c. 72, d. 75, e. 78
[A]:
c