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: if a and b are the roots of the equation x 2 - 9 x + 9 = 0, then the value of a 2 + b 2 is :
Options: a. 63, b. 24, c. 17, d. 6, e. 5
[A]: a


[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: cost of 2 bats and 3 balls is rs. 1300. the cost of 3 bats and 2 balls is rs. 1200. the cost of each balls is more than that of each bat by ?
Options: a. 50, b. 100, c. 110, d. 120, e. 130
[A]:
b