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.

[EX Q]: Problem: if an investor puts $ 700 in a savings account that earns 10 percent annual interest compounded semiannually, how much money will be in the account after one year ?
Options: a. $ 769.75, b. $ 771.75, c. $ 773.75, d. $ 775.75, e. $ 777.75
[EX A]: b

[EX Q]: Problem: maxwell leaves his home and walks toward brad ' s house. one hour later, brad leaves his home and runs toward maxwell ' s house. if the distance between their homes is 14 kilometers, maxwell ' s walking speed is 4 km / h, and brad ' s running speed is 6 km / h. what is the total time it takes maxwell before he meets up with brad ?
Options: a. 2, b. 4, c. 5, d. 6, e. 8
[EX A]: a

[EX Q]: Problem: a certain high school has 500 students. of these students, 50 are taking music, 20 are taking art, and 10 are taking both music and art. how many students are taking neither music nor art ?
Options: a. 430, b. 440, c. 450, d. 460, e. 470
[EX A]:
b