A and B can do a piece of work in 6 days and 4 days respectively. A started the work, worked at it for 2 days and then was joined by B. Find the total time taken to complete the work.
Given,
A can do a piece of work in = 6 days
B can do same piece of work in = 4 days
∵ Work done by A in 1 day =
∴ In 2 Days he finished = 
part of work
Remaining work = 
So, Remaining work will be finished by A and B in = 
days
∴ Total time taken to complete the work = 2 + 
= 3
days
16