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: set a contains all the even numbers between 2 and 50 inclusive. set b contains all the even numbers between 62 and 110 inclusive. what is the difference between the sum of elements of set b and the sum of the elements of set a ?
Options: a. 1500, b. 3100, c. 4400, d. 6200, e. 7400

A: a
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Q: Problem: a 10000 liter tank, half - full of water is being filled from a pipe with a flow rate of 1 kiloliter every 2 minutes. at the same time, the tank is losing water from two drains at a rate of 1 kiloliter every 4 minutes and every 6 minutes. how many minutes does it take to fill the tank completely ?
Options: a. 8, b. 12, c. 18, d. 24, e. 60

A: e
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Q: Problem: a man can row at 5 kmph in still water. if the velocity of current is 3 kmph and it takes him 1 hour to row to a place and come back, how far is the place ?
Options: a. 2.4 km, b. 2.9 km, c. 3.4 km, d. 4.4 km, e. 1.6 km

A:
e
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