A can do a work in 9 days and B can do the same work in 18 days. If they work together, in how many days will they complete the work? Choose the correct choice.
A) 4 days	B) 6 days	C) 8 days	D) 2 days	E) 9 days
6 days   6 days   One day's work of A and 6 days = 1/9 + 1/8 = (2+1)/18 = 1/6 So, the time taken to complete the work is 6 days.
<result>B</result>
A can do a work in 9 days and B can do the same work in 18 days. If they work together, in how many days will they complete the work?