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: the average weight of a group of persons increased from 48 kg to 51 kg, when two persons weighing 78 kg and 93 kg join the group. find the initial number of members in the group ?
Options: a. 87, b. 67, c. 23, d. 75, e. 25
[EX A]: c

[EX 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
[EX A]: d

[EX Q]: Problem: a certain company reported that the revenue on sales increased 40 % from 2000 to 2003, and increased 70 % from 2000 to 2005. what was the approximate percent increase in revenue for this store from 2003 to 2005 ?
Options: a. 50 %, b. 40 %, c. 35 %, d. 32 %, e. 21 %
[EX A]:
e