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: what number must be added to 6, 16 and 8 to get an average of 13 ?
Options: a. 23, b. 22, c. 44, d. 33, e. 55
b

Problem: of the diplomats who attended a summit conference: 20 spoke japanese, 32 did not speak russian and 20 % of the diplomats spoke neither japanese nor russian. if 10 % of the diplomats spoke both japanese and russian, then how many diplomats attended the conference ?
Options: a. 70, b. 96, c. 108, d. 120, e. 150
d

Problem: the l. c. m. of 2 numbers is 66. the numbers are in the ratio 2: 3. find their sum ?
Options: a. 36, b. 40, c. 48, d. 32, e. 55
e