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: a train covers a distance of 100 km in 1 hour. if its speed is decreased by 15 km / hr, the time taken by the car to cover the same distance will be ?
Options: a. 1 hr, b. 1 hr 10 min, c. 50 min, d. 1 hr 30 min, e. 1 hr 45 min

Answer: b


Question: Problem: what is the units digit of 26 ! + 50 ! + 4 ! + 4 ! ?
Options: a. 8, b. 6, c. 4, d. 2, e. 0

Answer: a


Question: Problem: roy is now 6 years older than julia and half of that amount older than kelly. if in 4 years, roy will be twice as old as julia, then in 4 years what would be roy ’ s age multiplied by kelly ’ s age ?
Options: a. 72, b. 84, c. 90, d. 96, e. 108

Answer:
e