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: if a person walks at 25 km / hr instead of 10 km / hr, he would have walked 20 km more. the actual distance traveled by him is :
Options: a. 50 km, b. 56 km, c. 13.3 km, d. 70 km, e. 80 km

SOLUTION: c

PROBLEM: Problem: if the simple interest on a certain amount in at 4 % rate 5 years amounted to rs. 2240 less than the principal. what was the principal ?
Options: a. 1500, b. 2500, c. 2507, d. 2800, e. 11500

SOLUTION: d

PROBLEM: Problem: the ratio of the present age of sandy to that of molly is 9: 2. eight years from now, the ratio of the ages of sandy to molly will be 5: 2. what was sandy ' s age 6 years ago ?
Options: a. 18, b. 21, c. 24, d. 27, e. 30

SOLUTION:
b