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: of 30 applicants for a job, 9 had at least 4 years ' experience, 18 had degrees, and 3 had less than 4 years ' experience and did not have a degree. how many of the applicants had at least 4 years ' experience and a degree ?
Options: a. 14, b. 10, c. 9, d. 7, e. 5
[EX A]: b

[EX 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. 7 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. 4538, b. s. 6342, c. s. 4518, d. s. 4530, e. s. 4517
[EX A]: b

[EX Q]: Problem: a train 110 m long is running with a speed of 90 km / h. in how many seconds will the train pass a man who is running at 9 km / h in the direction opposite to that in which the train is going ?
Options: a. 3, b. 4, c. 5, d. 6, e. 7
[EX A]:
b