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: the lcm of two numbers is 2310 and hcf is 55. if one of the numbers is 210. then what is the other number ?
Options: a. 715, b. 825, c. 330, d. 605, e. 465

Answer: d


Question: Problem: if ( x - 10 ) ( y - 5 ) ( z - 2 ) = 1000 then what is the least value of x + y + z ? if x, y, z are all integer no.
Options: a. 7, b. 8, c. 9, d. 10, e. 11

Answer: a


Question: Problem: excluding stoppages, the speed of a train is 45 kmph and including stoppages it is 31 kmph. of how many minutes does the train stop per hour ?
Options: a. 18.6, b. 27, c. 12, d. 121, e. 28

Answer:
a