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: kim has 3 pairs of shoes; each pair is a different color. if kim randomly selects 2 shoes without replacement from the 6 shoes, what is the probability that she will select 2 shoes of the same color ?
Options: a. 2 / 5, b. 1 / 5, c. 1 / 9, d. 1 / 10, e. 1 / 25
[EX A]: b

[EX Q]: Problem: four bells commence tolling together and toll at intervals of 2, 4, 6, 8 seconds respectively. in 18 minutes, how many times do they toll together ?
Options: a. 43, b. 44, c. 45, d. 46, e. 47
[EX A]: c

[EX Q]: Problem: a sum of rs 468.75 was lent out at simple interest and at the end of 1 year and 8 months, the total amount of rs 500 is received. find the rate of interest ?
Options: a. 3 %, b. 4 %, c. 5 %, d. 6 %, e. 7 %
[EX A]:
b