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 joes steakhouse the hourly wage for a chef is 20 % greater than that of a dishwasher, and the hourly wage of a dishwasher is half as much as the hourly wage of a manager. if a managers wage is $ 6.50 per hour, how much less than a manager does a chef earn each hour ?
Options: a. $ 2.6, b. $ 2.40, c. $ 3.40, d. $ 4.40, e. $ 5.40
[A]: a

[Q]: Problem: a train of 25 carriages, each of 60 meters length, when an engine also of 60 meters length is running at a speed of 60 kmph. in what time will the train cross a bridge 1.0 km long ?
Options: a. 2.5, b. 3, c. 5, d. 7, e. 9
[A]: a

[Q]: Problem: together, 15 type a machines and 7 type b machines can complete a certain job in 4 hours. together 8 type b machines and 15 type c machines can complete the same job in 11 hours. how many q hours would it take one type a machine, one type b machine, and one type c machine working together to complete the job ( assuming constant rates for each machine. ?
Options: a. 22 hours, b. 30 hours, c. 44 hours, d. 60 hours, e. it can not be determined from the information above.
[A]:
c