Answer:
The depth of the milk is 4cm when turned
Explanation:
First we need to figure out how much milk is inside the container. We can do this by finding the volume it takes up. The milk's depth is 12cm so the height is 12 instead of 15. The length and width remain the same (5 and 8)
5x8x12=480 cm^3
The volume of the milk is 480, so when the carton is turned, the milk's volume still is the same
When it is turned, the base changes. Now it is 8 and 15 for the length and width. We just need to find the height.
8x15xh=480
120h=480
h=4
The depth of the milk is 4cm when turned