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: 2.205 divided by 0.3 gives
Options: a. 7.35, b. 6.25, c. 8.15, d. 6.95, e. none of these
[A]: a

[Q]: Problem: if 20 typists can type 50 letters in 30 minutes, then how many letters will 40 typists working at the same rate complete in 1 hour ?
Options: a. 400, b. 500, c. 350, d. 250, e. 200
[A]: a

[Q]: Problem: mary can do a piece of work in 26 days. rosy is 30 % more efficient than mary. the number of days taken by rosy to do the same piece of work is ?
Options: a. 22, b. 20, c. 24, d. 26, e. 30
[A]:
b