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: In an office, 20 percent of the workers have at least 5 years of service, and a total of 16 workers have at least 10 years of service. If 90 percent of the workers have fewer than 10 years of service, how many of the workers have at least 5 but fewer than 10 years of service?

 Option A:  32

 Option B:  64

 Option C:  50

 Option D:  144

 Option E:  160

A: Option A
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Q: Question: If j and k are integers whose product is 400, which of the following statements must be true?

 Option A: n + k > 0

 Option B: n is not equal to k.

 Option C: Either n or k is a multiple of 10.

 Option D: If n is even, then k is odd.

 Option E: If j is odd, then k is even.

A: Option E
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Q: Question: Ashok borrowed some money at the rate of 6% p.a. for the first two years, at the rate of 9% p.a. for the next three years and at the rate of 14% p.a. for the period beyond five years. If he pays a total interest of 11,400/ - at the end of nine years, how much money did he borrow?

 Option A: 16,060

 Option B: 14,000

 Option C: 18,000

 Option D: 12,000

 Option E: None of these

A:
Option D
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