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.

[Q]: Problem: a bag of potatoes weighs 60 lbs divided by half of its weight. how much does the bag of potatoes weight ?
Options: a. 20 lb, b. 11 lb, c. 10 lb, d. 15 lb, e. 5 lb
[A]: b


[Q]: Problem: a shopkeeper sold 30 articles at the cost price of 35 articles. then find the profit % or lost %
Options: a. 12 %, b. 15 %, c. 16.67 %, d. 18 %, e. 22 %
[A]: c


[Q]: Problem: jack and jill are marathon runners. jack can finish a marathon ( 42 km ) in 7 hours and jill can run a marathon in 4.2 hours. what is the ratio of their average running speed ? ( jack: jill )
Options: a. 14 / 15, b. 15 / 14, c. 5 / 5, d. 5 / 4, e. can not be determined
[A]:
c