TASK DEFINITION: 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.
PROBLEM: Problem: the average age of a family of 5 members is 20 years. if the age of the youngest member be 10 years then what was the average age of the family at the time of the birth of the youngest member ?
Options: a. 13.5, b. 14, c. 15, d. 12.5, e. none

SOLUTION: d

PROBLEM: Problem: sandy walked 20 meters towards south. then sandy turned to her left and walked 20 meters. she then turned to her left and walked 20 meters. she then turned to her right and walked 25 meters. what distance is she from the starting point and in which direction ?
Options: a. 35 m east, b. 35 m north, c. 30 m west, d. 45 m west, e. 45 m east

SOLUTION: e

PROBLEM: Problem: if the diameter of circle r is 40 % of the diameter of circle s, the area of circle r is what percent of the area of circle s ?
Options: a. 16 %, b. 18 %, c. 20 %, d. 22 %, e. 24 %

SOLUTION:
a