A, B and C can do a piece of work in 14, 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 choice from the following options:
A) 7.6 days	B) 7.7 days	C) 6.7 days	D) 5.7 days	E) 8.7 days
x/14 + x/30 + x/40 = 1   x = 7.7 days   ANSWER:7.7 days
<result>B</result>
A, B and C can do a piece of work in 14, 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?