A can do a piece of work in 20 days and B can do it in 15 days and C can do it 20 days. They started the work together and A leaves after 2 days and B leaves after 4 days from the beginning. How long will work lost?  Pick:
A) 10 2/5  B) 10 2/0  C) 12 2/3  D) 10 2/1  E) 10 2/3
2/20 + 4/15 + x/20 = 1   x = 38/3 = 12 2/3 Answer: 12 2/3
<result>C</result>
A can do a piece of work in 20 days and B can do it in 15 days and C can do it 20 days. They started the work together and A leaves after 2 days and B leaves after 4 days from the beginning. How long will work lost?