Question:
"For the following exercises, consider a right cone that is leaking water. The dimensions of the conical tank are a height of 16 ft and a radius of 5 ft. How fast does the depth of the water change when the water is 10 ft high if the cone leaks water at a rate of 10 ft³/min?"

My work: I just did this problem and got -333 pi/3 ft per min as the answer. But the answer key says it is 128/125pi ft per min. Can someone work through this problem and explain what I did wrong? :(

I'm still learning and trying to understand this concepts of (calculus specific) rates of change, so detailed explanation of what to do and why would be so helpful!​