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.

[Q]: Problem: two positive integers differ by 4, and sum of their reciprocals is 2. then one of the numbers is
Options: a. a. 3, b. 2, c. c. 5, d. d. 21, e. e. 28
[A]: b


[Q]: Problem: of 30 applicants for a job, 9 had at least 4 years ' experience, 18 had degrees, and 3 had less than 4 years ' experience and did not have a degree. how many of the applicants had at least 4 years ' experience and a degree ?
Options: a. 14, b. 10, c. 9, d. 7, e. 5
[A]: b


[Q]: Problem: two numbers are in the ratio 3: 4. if their l. c. m. is 84. what is sum of the numbers ?
Options: a. 49, b. 56, c. 76, d. 84, e. 85
[A]:
a