A can complete a piece of work in 18 days and B can complete the same work in half time taken by A. Then, working together, what part of the same work they can complete in a day?
A's 1 day's work = `1/18`
B's 1 day's work = `1/9`
(A+ B)'s 1 day's work = `1/9+1/18=3/18=1/6`