A can do a piece of work in 30 days. He works at it for 5 days and then B finishes it in 20 days. In what time can A and B together it?
Choose the correct option
A) 15 1/3 days  B) 13 1/3 days  C) 19 1/3 days  D) 11 1/3 days  E) 12 1/3 days
13 1/3 days   13 1/3 days   5/30 + 20/x = 1   x = 24   1/30 + 1/24 = 3/40   40/3 = 13 1/3 days
<result>B</result>
A can do a piece of work in 30 days. He works at it for 5 days and then B finishes it in 20 days. In what time can A and B together it?