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) 15 days	B) 14 days	C) 13 days	D) 11 days	E) 10 days
Explanation:   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?