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: a farmer spent $ 35 on feed for chickens and goats. he spent 40 % money on chicken feed, which he bought at a 50 % discount off the full price, and spent the rest on goat feed, which he bought at full price. if the farmer had paid full price for both the chicken feed and the goat feed, what amount would he have spent on the chicken feed and goat feed combined ?
Options: a. $ 37.80, b. $ 49, c. $ 39.20, d. $ 39.50, e. $ 40.60

SOLUTION: b

PROBLEM: Problem: if the population of a certain country increases at the rate of one person every 15 seconds, by how many persons does the population increase in 25 minutes ?
Options: a. 80, b. 100, c. 150, d. 240, e. 300

SOLUTION: b

PROBLEM: Problem: at the beginning of a year, the owner of a jewel shop raised the price of all the jewels in his shop by x % and lowered them by x %. the price of one jewel after this up and down cycle reduced by rs. 100. the owner carried out the same procedure after a month. after this second up - down cycle, the price of that jewel was rs. 2304. find the original price of that jewel ( in rs. )
Options: a. 2500, b. 550, c. 2600, d. 2650, e. none of these

SOLUTION:
a