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: there are 27 different 3 - digit integers that can be formed using only the digits 3, 4 and 5. if all 27 of the integers were listed, what would their sum be ?
Options: a. 11,888, b. 11,988, c. 12,088, d. 12,188, e. 12,288
[EX A]: b

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

[EX Q]: Problem: two kinds of vodka are mixed in the ratio 1: 5 and 5: 1 and they are sold fetching the profit 10 % and 20 % respectively. if the vodkas are mixed in equal ratio and the individual profit percent on them are increased by 4 / 3 and 5 / 3 times respectively, then the mixture will fetch the profit of
Options: a. 21 %, b. 20 %, c. 21 % 18 %, d. 23 %, e. can not be determined
[EX A]:
c