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.

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
Option A

Question: In 120 m race, A covers the distance in 36 seconds and B in 45 seconds. In this race A beats B by:

 Option A: 24 m

 Option B: 25 m

 Option C: 22.5 m

 Option D: 9 m

 Option E: 12 m
Option A

Question: The sum t of prime numbers that are greater than 60 but less than 70 is

 Option A:  67

 Option B:  128

 Option C:  191

 Option D:  197

 Option E:  260

Option B