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: if x and y are positive integers and 3 + x + y + xy = 17, what is the value of x + y ?
Options: a. 3, b. 5, c. 6, d. 8, e. 9
c

Problem: micheal and adam can do together a piece of work in 20 days. after they have worked together for 15 days micheal stops and adam completes the remaining work in 10 days. in how many days micheal complete the work separately.
Options: a. 40 days, b. 100 days, c. 120 days, d. 110 days, e. 90 days
a

Problem: an association of mathematics teachers has 1,260 members. only 525 of these members cast votes in the election for president of the association. what percent of the total membership voted for the winning candidate if the winning candidate received 65 percent of the votes cast ?
Options: a. 75 %, b. 58 %, c. 42 %, d. 27.08 %, e. 25 %

d