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: when a certain number x is divided by 61, the remainder is 24. what is the remainder when x is divided by 5 ?
Options: a. 2, b. 3, c. 4, d. 5, e. 6
[EX A]: c

[EX Q]: Problem: if the ratio of two number is 6: 7 and lcm of the number is 450 then what is the number.
Options: a. 11, b. 20, c. 25, d. 30, e. 35
[EX A]: a

[EX Q]: Problem: a boy perform 5 times a reaction and his reading are 2, 2.1, 2, 2.2 but unfortunately 5 th reading clearly not visible because a drop of chemical fall onto it. but luckily he have mean of all reading which is 2. please help him in finding 5 th reading.
Options: a. 2, b. 1.7, c. 1.9, d. 1.8, e. 2.1
[EX A]:
b