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: two trains, one from howrah to patna and the other from patna to howrah, start simultaneously. after they meet, the trains reach their destinations after 10 hours and 8 hours respectively. the ratio of their speeds is
Options: a. 4: 9, b. 4: 3, c. 4: 12, d. 4: 8, e. 4: 5
[A]: e


[Q]: Problem: a lady grows broccoli in her garden that is in the shape of a square. each broccoli takes 1 square foot of area in her garden. this year, she has increased her output by 79 broccoli when compared to last year. the shape of the area used for growing the broccoli has remained a square in both these years. how many broccoli did she produce this year ?
Options: ['a. 1600', 'b. 1500', 'c. 1650', 'd. 1700', 'e. can not be determined']
[A]: a


[Q]: Problem: 15 men take 21 days of 8 hrs. each to do a piece of work. how many days of 5 hrs. each would it take for 21 women if 3 women do as much work as 2 men ?
Options: a. 30, b. 20, c. 16, d. 26, e. 36
[A]:
e