A and B can together finish a work 30 days. They worked together for 20 days and then B left. After another 20 days, A finished the remaining work. In how many days A alone can finish the work?

[A]. 40

[B]. 50

[C]. 54

[D]. 60

✅ The correct answer is option D.
(A + B)’s 20 day’s work =

1
x 20

=
2
.

30
3

Remaining work =

1 –
2

=
1
.

3
3

Now,
1
work is done by A in 20 days.

Therefore, the whole work will be done by A in (20 x 3) = 60 days.

126. A and B can together finish a work 30 days. They worked together for 20 days and then B left. After another 20 days, A finished the remaining work. In how many days A alone can finish the work?