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: How many odd 4-digit positive integers R that are multiples of 5 can be formed without using the digit 3?

 Option A: 648

 Option B: 729

 Option C: 900

 Option D: 1296

 Option E: 3240

A: Option A
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Q: Question: A and B go around a circular track of length 600 m on a cycle at speeds of 30 kmph and 60 kmph. After how much time will they meet for the first time at the starting point?

 Option A: 120 sec

 Option B: 176 sec

 Option C: 178 sec

 Option D: 72 sec

 Option E: 189 sec

A:
Option D
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