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.
--------
Question: Problem: a man can row upstream at 25 kmph and downstream at 55 kmph, and then find the speed of the man in still water ?
Options: a. 65, b. 40, c. 30, d. 78, e. 38

Answer: b

Question: Problem: a gardener grows cabbages in her garden that is in the shape of a square. each cabbage takes 1 square feet of area in her garden. this year, she has increased her output by 193 cabbages as compared to last year. the shape of the area used for growing the cabbages has remained a square in both these years. how many cabbages did she produce this year ?
Options: a. 8,208, b. 9,409, c. 11,424, d. 12,586, e. can not be determined

Answer: b

Question: Problem: kim finds a 2 - meter tree branch and marks it off in thirds and fifths. she then breaks the branch along all the markings and removes one piece of every distinct length. what fraction of the original branch remains ?
Options: a. 3 / 5, b. 2 / 5, c. 7 / 5, d. 1 / 2, e. 8 / 15

Answer:
a