Answer:
15 hours
Explanation:
Kelsey + 4 sisters = 5 girls
Each of the 5 girls spent three hours cleaning
Usually, I would do 5 x 3 = c, but since we need to use a division equation, we should use c / 5 = 3 OR c / 3 = 5.
c/5 = 3
3 x 5 = 15
Check: 15/ 5 = 3