8/20 + 6/x = 1
X = 10 days
A can do a piece of work in 20 days. When he had worked for 2 days B joins him. If the complete work was finished in 8 days. In how many days B alone can finish the work?

(1) 18
(2) 77
(3) 66
(4) 55
(5) 10