instruction:
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.
question:
Problem: if the simple interest on a certain sum of money for 6 years is one fifth of the sum, then the rate of interest per annum is
Options: a. 3.3 %, b. 7.2 %, c. 6.1 %, d. 5.0 %, e. 3.1 %
answer:
a

question:
Problem: how many positive integer solutions does the equation 8 x + 2 y = 100 have ?
Options: a. 50, b. 84, c. 16, d. 35, e. 14
answer:
b

question:
Problem: water boils at 212 f or 100 c and ice melts at 32 f or 0 c. if the temperature of a pot of water is 55 c, what is the temperature of the pot of water in f ?
Options: a. 116 f, b. 125 f, c. 131 f, d. 138 f, e. 145 f
answer:
c