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.

[EX Q]: Problem: a, b, c can complete a piece of work in 24, 8,12 days. working together, they complete the same work in how many days ?
Options: a. 4, b. 4 / 5, c. 7 / 9, d. 10, e. 24 / 7
[EX A]: a

[EX Q]: Problem: find the cost of fencing around a circular field of diameter 32 m at the rate of rs. 2 a meter ?
Options: a. 201, b. 132, c. 772, d. 592, e. 261
[EX A]: a

[EX Q]: Problem: the marks obtained by vijay and amith are in the ratio 8: 5 and those obtained by amith and abhishek in the ratio of 3: 2. the marks obtained by vijay and abhishek are in the ratio of ?
Options: a. 12: 5, b. 12: 1, c. 6: 5, d. 12: 2, e. 6: 3
[EX A]:
a