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: if p ( a. = 5 / 7 and p ( b. = 2 / 5, find p ( a n b. if a and b are independent events.
Options: a. 7 / 25, b. 3 / 25, c. 8 / 25, d. 2 / 7, e. 3 / 17
[A]: d

[Q]: Problem: what is the units digit of 26 ! + 50 ! + 4 ! + 4 ! ?
Options: a. 8, b. 6, c. 4, d. 2, e. 0
[A]: a

[Q]: Problem: dick and jane each saved $ 5,000 in 1989. in 1990 dick saved 10 percent more than in 1989, and together he and jane saved a total of $ 10,000. approximately what percent less did jane save in 1990 than in 1989 ?
Options: a. 10 %, b. 15 %, c. 20 %, d. 25 %, e. 30 %
[A]:
a