A and B can do a work in 5 days and 10 days respectively. A starts the work and B joins him after 2 days. In how many days can they complete the remaining work?
(A + B)’s 1 day’s work = ( 1 + 1 ) = 1 .
15 10 6
Work done by A and B in 2 days = ( 1 x 2 ) = 1 .
6 3
Remaining work = ( 1 – 1 ) = 2 .
3 3
Now, 1 work is done by A in 1 day.
15
Therefore 2 work will be done by a in ( 15 x 2 ) = 10 days.
3 3
Hence, the total time taken = (10 + 2) = 12 days.
Answer: 12 days.
Explanation:
(A + B)’s 1 day’s work = ( 1 + 1 ) = 1 .
15 10 6
Work done by A and B in 2 days = ( 1 x 2 ) = 1 .
6 3
Remaining work = ( 1 – 1 ) = 2 .
3 3
Now, 1 work is done by A in 1 day.
15
Therefore 2 work will be done by a in ( 15 x 2 ) = 10 days.
3 3
Hence, the total time taken = (10 + 2) = 12 days.
4