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: 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: out of 40 applicants to a law school, 15 majored in political science, 20 had a grade point average higher than 3.0, and 10 did not major in political science and had a gpa equal to or lower than 3.0. how many e applicants majored in political science and had a gpa higher than 3.0 ?
Options: a. 5, b. 10, c. 15, d. 25, e. 35
a

Problem: the ratio between x and y is 7 / 5; x is multiplied by y and y is multiplied by x, what is the ratio between the new values of x and y ?
Options: a. 7 / 5, b. 5 / 7, c. 1, d. 49 / 25, e. it can not be determined

c