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: a bag contains 21 toys numbered 1 to 21. a toy is drawn and then another toy is drawn without replacement. find the probability that both toys will show even numbers.
Options: a. 5 / 21, b. 9 / 42, c. 6 / 22, d. 4 / 21, e. 3 / 21
[EX A]: b

[EX Q]: Problem: the denominator of a fraction is 7 greater than the numerator. if the numerator and the denominator are increased by 4, the resulting fraction is equal to 5 â  „ 6. what is the value of the original fraction ?
Options: a. 23 / 30, b. 25 / 32, c. 31 / 38, d. 37 / 44, e. 47 / 54
[EX A]: c

[EX Q]: Problem: a metallic sheet is of rectangular shape with dimensions 48 m x 36 m. from each of its corners, a square is cut off so as to make an open box. if the length of the square is 4 m, the volume of the box ( in m 3 ) is :
Options: a. 4480, b. 5120, c. 6420, d. 8960, e. 7960
[EX A]:
a