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: at what price must an article costing rs. 47.50 be marked in order that after deducting 7 % from the list price. it may be sold at a profit of 25 % on the cost price ?
Options: a. 63.84, b. 62.6, c. 62.1, d. 62.7, e. 62.2
[A]: a


[Q]: Problem: points a, b, c, and d, in that order, lie on a line. if ab = 3 cm, ac = 4 cm, and bd = 8 cm, what is cd, in centimeters ?
Options: a. 7, b. 2, c. 3, d. 4, e. 5
[A]: a


[Q]: Problem: a work as fast as b. if b can complete a work in 8 days independently, the number of days in which a and b can together finish the work in ?
Options: a. 2 days, b. 2 2 / 3 days, c. 4 days, d. 5 days, e. 6 days
[A]:
b