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 can do a piece of work in 4 hours; b and c together can do it in 3 hours, while a and c together can do it 2 hours. how long will b alone take to do it ?
Options: a. 8 hours, b. 10 hours, c. 12 hours, d. 24 hours, e. none of these

SOLUTION: c

PROBLEM: Problem: each of the three people individually can complete a certain job in 3, 4, and 6 hours, respectively. what is the lowest fraction of the job that can be done in 1 hour by 2 of the people working together at their respective rates ?
Options: a. 1 / 3, b. 9 / 20, c. 8 / 15, d. 5 / 12, e. 2 / 3

SOLUTION: d

PROBLEM: Problem: there is a train and car. the ratio between the speed of a train & a car is 16: 15 respectively. also, a bus covered a distance of 320 km in 5 hours. the speed of the bus is 4 / 5 th of the speed of the train. how many kilometers will the car cover in 7 hours ?
Options: a. 375, b. 425, c. 475, d. 525, e. 575

SOLUTION:
d