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.

[EX 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
[EX A]: Option A

[EX Q]: Question: A train 125m long takes 6 sec to cross a man walking at 5kmph in a direction opposite to that of the train. Find the speed of the train?

 Option A: 65kmph

 Option B: 70kmph

 Option C: 75kmph

 Option D: 80kmph

 Option E: 85kmph
[EX A]: Option B

[EX Q]: Question: The owner of a furniture shop charges his customer 30% more than the cost price. If a customer paid Rs. 8450 for a computer table, then what was the cost price of the computer table?

 Option A: Rs. 5725

 Option B: Rs. 5275

 Option C: Rs. 6275

 Option D: Rs. 6500

 Option E: None of these
[EX A]:
Option D