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: cost is expressed by the formula tb ^ 4. if b is doubled, the new cost w is what percent of the original cost ?
Options: a. w = 200, b. w = 600, c. w = 800, d. w = 1600, e. w = 50

SOLUTION: d

PROBLEM: Problem: a solid yellow stripe is to be painted in the middle of a certain highway. if 1 gallon of paint covers an area of q square feet of highway, how many gallons of paint will be needed to paint a stripe of t inches wide on a stretch of highway m miles long ? ( 1 mile = 5,280 feet and 1 foot = 12 inches )
Options: ['a. ( 5,280 mt ) / 12 q', 'b. ( 5,280 pt ) / 12 m', 'c. ( 5,280 pmt ) / 12', 'd. ( 5,280 ) ( 12 m ) / pt', 'e. ( 5,280 ) ( 12 p ) / mt']

SOLUTION: a

PROBLEM: Problem: increasing the original price of a certain item by 20 percent and then increasing the new price by 20 percent is equivalent to increasing the original price by what percent ?
Options: a. 31.25, b. 37.5, c. 50.0, d. 52.5, e. 44.0

SOLUTION:
e