A, B and C can do a piece of work in 24, 30 and 40 days respectively. They start the work together but C leaves 4 days before the completion of the work. In how many days is the work done?
Choose the correct answer:  A) 22 days  B) 77 days  C) 88 days  D) 11 days  E) 18 days
x/24 + x/30 + x/40 = 1   x = 11 days   Answer:11 days
<result>D</result>
A, B and C can do a piece of work in 24, 30 and 40 days respectively. They start the work together but C leaves 4 days before the completion of the work. In how many days is the work done?