Answer:
4 hours and 57 minutes.
Step-by-step explanation:
The least common multiple of 9 and 11 is 99
.
In 99 hours, Sue could fill 11 orders (99 divided by 11)
Felipe could fill 9 orders (
99 divided by 11
), making a total of
9
+
11
=
20 orders if they both work.
So for both of them working to fill one order would take:
99
/20 hours.
To express in hours and minutes:
99
/20
=
80
/20
+
19
/20
=
4
+ 3
⋅
19
/3
⋅
20
=
4
+ 57
/60
That's 4 hours and 57 minutes, since a sixtieth of an hour is one minute.
