A's one day's work = 1/30
B's one day's work = 1/45
(A + B)'s one day's work = 1/30 + 1/45 = 1/18
The part of the work completed in 5 days = 5 (1/18) = 5/18.
Two persons A and B can complete a piece of work in 30 days and 45 days respectively. If they work together, what part of the work will be completed in 5 days?

a. 5/18
b. 1/6
c. 1/4
d. 1/9
e. 2/6