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: how many 4 - digit numbers that do not contain the digits 2, 3, 4, 5, 6, or 7 are there ?
Options: a. 168, b. 176, c. 184, d. 192, e. 200

Answer: d


Question: Problem: a bag contains 10 green and 8 white balls. if two balls are drawn simultaneously, the probability that both are of the same colour is
Options: a. 8 / 15, b. 21 / 44, c. 3 / 5, d. 11 / 15, e. 7 / 15

Answer: b


Question: Problem: a train 110 m long is running with a speed of 36 km / hr. in what time will it pass a man who is running at 6 km / hr in the direction opposite to that in which the train is going ?
Options: a. 5, b. 6, c. 7, d. 9, e. 5

Answer:
d