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: a person crosses a 800 m long street in 5 minutes. what is his speed in km per hour ?
Options: a. 1.23, b. 2.86, c. 4.36, d. 9.25, e. 9.61

A: e
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Q: Problem: find the sum of first 89 odd numbers
Options: a. 7921, b. 4800, c. 7900, d. 4980, e. 4960

A: a
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Q: Problem: a clock shows the time as 10 a. m. if the minute hand gains 5 minutes every hour, how many minutes will the clock gain by 6 p. m. ?
Options: a. 45 minutes, b. 55 minutes, c. 35 minutes, d. 25 minutes, e. 40 minutes

A:
e
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