Answer:
Last week she work
.
Explanation:
Given:
Last week Stacy earned $24 for baby sitting for hours in her part time job at Burger city she work 12 hours and earned $78.
Now, to find the total hours she work last week.
As, given she work 12 hours and earned $78.
So, to solve by using unitary method:
If she earned $78 in working 12 hours.
So, she earned $1 in working =

Thus, she earned $24 in working =



Therefore, last week she work
.