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.

Problem: a certain roller coaster has 6 cars, and a passenger is equally likely to ride in any 1 of the 6 cars each time that passenger rides the roller coaster. if a certain passenger is to ride the roller coaster 6 times, what is the probability that the passenger will ride in each of the 6 cars ?
Options: a. 3 / 1944, b. 1 / 96, c. 2 / 96, d. 1 / 1944, e. 1
a

Problem: in an office, totally there are 2800 employees and 25 % of the total employees are males. 30 % of the males in the office are at - least 50 years old. find the number of males aged below 50 years ?
Options: a. 390, b. 490, c. 400, d. 460, e. none of these
b

Problem: a boy swims downstream 56 km and upstream 42 km taking 7 hours each time; what is the speed of the current ?
Options: a. 5, b. 4, c. 3, d. 2, e. 1

e