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: in one hour, a boat goes 19 km / hr along the stream and 9 km / hr against the stream. the speed of the boat in still water ( in km / hr ) is :
Options: a. 12 kmph, b. 13 kmph, c. 14 kmph, d. 15 kmph, e. 16 kmph

SOLUTION: c

PROBLEM: Problem: how many quarters are equal to 7 dollars ?
Options: a. 1, b. 28, c. 12, d. 9, e. 7

SOLUTION: b

PROBLEM: Problem: what is the rate percent when the simple interest on rs. 800 amount to rs. 128 in 4 years ?
Options: a. 5 %, b. 3 %, c. 4 %, d. 9 %, e. 1 %

SOLUTION:
c