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: the dimensions of a room are 25 feet * 15 feet * 12 feet. what is the cost of white washing the four walls of the room at rs. 10 per square feet if there is one door of dimensions 6 feet * 3 feet and three windows of dimensions 4 feet * 3 feet each ?
Options: a. s. 9060, b. s. 4520, c. s. 4527, d. s. 4530, e. s. 4521
[A]: a


[Q]: Problem: what is the total number of integers between 200 and 500 that are divisible by 25 ?
Options: a. 20, b. 25, c. 14, d. 15, e. 18
[A]: d


[Q]: Problem: the average marks of a class of 35 students is 40 and that of another class of 45 students is 60. find the average marks of all the students ?
Options: a. 52.6, b. 52.4, c. 52.1, d. 51.2, e. 52.9
[A]:
d