A can do a piece of work in 20 days; B can do the same in 30 days. A started alone but left the work after 10 days, then B worked at it for 10 days. C finished the remaining work in 10 days. C alone can do the whole work in?	Choose the most appropriate option:	A) 70 days	B) 65 days	C) 40 days	D) 50 days	E) 60 days
10/20 + 10/30 + 10/x = 1   x = 60 days   ANSW60 daysR:60 days
<result>E</result>
A can do a piece of work in 20 days; B can do the same in 30 days. A started alone but left the work after 10 days, then B worked at it for 10 days. C finished the remaining work in 10 days. C alone can do the whole work in?