128. X can do a piece of work in 40 days. He works at it for 8 days and then Y finished it in 16 days. How long will they together take to complete the work?

✅ The correct answer is option A.
Work done by X in 8 days =

1
x 8

=
1
.

40
5

Remaining work =

1 –
1

=
4
.

5
5

Now,
4
work is done by Y in 16 days.

5

Whole work will be done by Y in

16 x
5

= 20 days.

4

X’s 1 day’s work =
1
, Y’s 1 day’s work =
1
.

40
20

(X + Y)’s 1 day’s work =

1
+
1

=
3
.

40
20
40

Hence, X and Y will together complete the work in

40

= 13
1
days.

3
3