A man can do a piece of work in 5days, but with the help of his son, he can finish it in 2days. In what time can the son do it alone? Choose the correct choice from the following choices
A) 3 1/3 B) 5 1/2 C) 7 1/2 D) 6 E) 9 1/2
Son's 1day work = 1/2 - 1/5 = 3/10   Son alone can do the work in 10/3days = 3 1/3 days   3 1/3nswer is 3 1/3
<result>A</result>
A man can do a piece of work in 5days, but with the help of his son, he can finish it in 2days. In what time can the son do it alone?