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: if a randomly selected positive single digit multiple of 3 is multiplied by a randomly selected prime number less than 20, what is the probability w that this product will be a multiple of 45 ?
Options: a. 1 / 32, b. 1 / 28, c. 1 / 24, d. 1 / 16, e. 1 / 14

Answer: c


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: if y > 0, ( 6 y ) / 20 + ( 3 y ) / 10 is what percent of y ?
Options: a. 40 %, b. 50 %, c. 60 %, d. 70 %, e. 80 %

Answer:
c