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: The total of the ages of Amar, Akbar and Anthony is 30 years. What was the total of their ages three years ago ?

 Option A: 20 years

 Option B: 28 years

 Option C: 71 years

 Option D: 21 years

 Option E: 31 years

A: Option D
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Q: Question: John left home and drove at the rate of 45 mph for 2 hours. He stopped for lunch then drove for another 3 hours at the rate of 45 mph to reach his destination. How many miles did John drive?

 Option A: 235 miles.

 Option B: 245 miles.

 Option C: 225 miles.

 Option D: 265 miles.

 Option E: 275 miles.

A: Option C
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Q: Question: What is the units digit of the expression 14^7−17^4?

 Option A:  0

 Option B:  3

 Option C:  4

 Option D:  8

 Option E:  6

A:
Option D
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