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.
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Question: Question: What is the units digit of 18! + 5 ?

 Option A: 2

 Option B: 3

 Option C: 4

 Option D: 5

 Option E: 6

Answer: Option D


Question: Question: A man can do a piece of work in 5 days, but with the help of his son he can do it in 3 days. In what time can the son do it alone ?

 Option A: 13/2

 Option B: 19/2

 Option C: 21/2

 Option D: 15/2

 Option E: None

Answer: Option C


Question: Question: The probability of a lottery ticket being a prized ticket is 0.2. When 4 tickets are purchased, the probability of winning a prize on atleast one ticket is

 Option A: 0.5928

 Option B: 0.5904

 Option C: 0.5297

 Option D: 0.5297

 Option E: 0.5101

Answer:
Option B