A can do a work in 3 days. B can do the same work in 6 days. If both A & B are working together in how many days they will finish the work?  Select the correct option
A) 3
B) 5
C) 4
D) 2
E) 6
A rate = 1/3   B rate = 1/6   (A+B) rate = (1/3)+(1/6) = 1/2   A &amp; B finish the work in 2days   correct option is 2
<result>D</result>
A can do a work in 3 days. B can do the same work in 6 days. If both A & B are working together in how many days they will finish the work?