You are given a math word problem and you are supposed to make use of mathematical concepts like probability, combinatorics, linear equations, sequences/series, or simple operators like addition, subtraction, division, or multiplication to answer the given question. Choose the best option from the 5 given options and report that option.

Q: Question: A can complete the job in 4 hours and B can complete the same job in 3 hours. A works for 1 hour and then B joins and both complete the job. What fraction of the job did B complete

 Option A: 1/7

 Option B: 3/10

 Option C: 1/2

 Option D: 5/6

 Option E: 8/9

A: Option A
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Q: Question: If a college has 15 staff for every 700 students, then what is the number of staff for 1400 students?

 Option A: 30

 Option B: 14

 Option C: 12

 Option D: 17

 Option E: 19

A: Option A
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Q: Question: 3, k, 20, m, 4, n
In the list above, k, m, and n are three distinct positive integers and the average (arithmetic mean) of the six numbers in the list is 8. If the median of the list is 6.5, which of the following CANNOT be the value of k, m, or n ?

 Option A: 9

 Option B: 8

 Option C: 7

 Option D: 6

 Option E: 5

A:
Option E
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