110. A can do a work in 15 days and B in 20 days. If they work on it together for 4 days, then the fraction of the work that is left is :

✅ The correct answer is option D.
A’s 1 day’s work =
1
;

15

B’s 1 day’s work =
1
;

20

(A + B)’s 1 day’s work =

1
+
1

=
7
.

15
20
60

(A + B)’s 4 day’s work =

7
x 4

=
7
.

60
15

Therefore, Remaining work =

1 –
7

=
8
.

15
15