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: in traveling from a dormitory to a certain city, a student went 1 / 3 of the way by foot, 3 / 5 of the way by bus, and the remaining 2 kilometers by car. what is the distance, in kilometers, from the dormitory to the city ?
Options: a. 30, b. 45, c. 60, d. 90, e. 120
a

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

Problem: paul ' s income is 40 % less than rex ' s income, quentin ' s income is 20 % less than paul ' s income, and sam ' s income is 40 % less than paul ' s income. if rex gave 60 % of his income to sam and 40 % of his income to quentin, quentin ' s new income would be what fraction of sam ' s new income ?
Options: a. 11 / 12, b. 13 / 17, c. 13 / 19, d. 12 / 19, e. 11 / 19

a