A, B and C can do a piece of work in 24 days, 30 days and 60 days respectively. They began the work together but C left 4 days before the completion of the work. In how many days was the work completed?  Select:	A) 10 days	B) 11 days	C) 13 days	D) 21 days	E) 31 days
One day work of A, B and C = 1/24 + 1/30 + 1/60 = 11/120 Work done by A and B together in the last 4 days = 4*(1/24 + 1/30) = 3/10   Remaining work = 7/10   The number of days required for this initial work = 7 days.   The total number of days required = 4 + 7= 
<gadget id="calculator">4 + 7</gadget>
<output>11</output>
11 days.   ANSWER:11 days
<result>B</result>
A, B and C can do a piece of work in 24 days, 30 days and 60 days respectively. They began the work together but C left 4 days before the completion of the work. In how many days was the work completed?