A, B and C can do a piece of work in 24 days, 30 days and 40 days respectively. They began the work together but C left 10 days before the completion of the work. In how many days was the work completed?  Choose the correct answer:	A) 12.5 days	B) 16 days	C) 18 days	D) 11 days	E) 38 days
One day work of A, B and C = 1/24 + 1/30 + 1/40 = 1/10 Work done by A and B together in the last 10 days = 10*(1/24 + 1/30) = 3/4   Remaining work = 1/4   The number of days required for this initial work = 2.5 days.   The total number of days required = 10 + 2.5= 
<gadget id="calculator">10 + 2.5</gadget>
<output>12.5</output>
12.5 days.   12.5 daysnswer: 12.5 days
<result>A</result>
A, B and C can do a piece of work in 24 days, 30 days and 40 days respectively. They began the work together but C left 10 days before the completion of the work. In how many days was the work completed?