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: 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: of 30 applicants for a job, 9 had at least 4 years ' experience, 18 had degrees, and 3 had less than 4 years ' experience and did not have a degree. how many of the applicants had at least 4 years ' experience and a degree ?
Options: a. 14, b. 10, c. 9, d. 7, e. 5
b

Problem: in one alloy there is 12 % chromium while in another alloy it is 8 %. 35 kg of the first alloy was melted together with 40 kg of the second one to form a third alloy. find the percentage of chromium in the new alloy.
Options: a. 8.8 %, b. 9.75 %, c. 9.2 %, d. 8.6 %, e. 8.4 %

b