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.

[EX Q]: Problem: the average weight of a, b and c is 43 kg. if the average weight of a and b be 48 kg and that of b and c be 42 kg, then the weight of b is :
Options: a. 55 kg, b. 53 kg, c. 49 kg, d. 52 kg, e. 51 kg
[EX A]: e

[EX Q]: Problem: a fruit - salad mixture consists of apples, peaches, and grapes in the ratio 6: 5: 4, respectively, by weight. if 60 pounds of the mixture is prepared, the mixture includes how many more pounds of apples than grapes ?
Options: a. 15, b. 12, c. 8, d. 6, e. 4
[EX A]: c

[EX Q]: Problem: a car runs at the speed of 25 km per hour when not serviced and runs at 75 kmph when serviced. after servicing the car covers a certain distance in 5 hours. how much time will the car take to cover the same distance when not serviced ?
Options: a. 8 hours, b. 16 hours, c. 15 hours, d. 7 hours, e. none
[EX A]:
d