Data
Milk drank = 1 1/2 twice a day
Volume in a container = 15 cups
Number of days the contaier will be empty = ?
Procedure
To solve this problem just divide the volume of the container by the milk drank by the child.
As the child drinks 1 1/2 twice a day, the total milk drank in a day will be = 2 x 1 1/2 = 3
Division 15/3 = 5
Solution: The container will be empty in 5 days