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.

Input: Consider Input: Problem: a, b, c can complete a piece of work in 24, 8,12 days. working together, they complete the same work in how many days ?
Options: a. 4, b. 4 / 5, c. 7 / 9, d. 10, e. 24 / 7

Output: a


Input: Consider Input: Problem: in a group of 100 people, 90 have an age of more 30 years, and the others have an age of less than 20 years. if a person is selected at random from this group, what is the probability the person ' s age is less than 20 ?
Options: a. 0.1, b. 0.55, c. 0.65, d. 0.75, e. 0.85

Output: a


Input: Consider Input: Problem: the length of a rectangle is one fourth of the radius of a circle. the radius of the circle is equal to the side of the square, whose area is 784 sq. units. what is the area ( in sq. units ) of the rectangle if the rectangle if the breadth is 5 units ?
Options: ['a. 35 sq. units', 'b. 45 sq. units', 'c. 55 sq. units', 'd. 50 sq. units', 'e. 40 sq. units']


Output: a