Jackson uses the Fermi process to estimate the number of buckets of gravel he could store in a warehouse. The buckets are shaped like cylinders. The warehouse is shaped like a rectangular prism.

He estimates the buckets have a height of 25 in. and a diameter of 20 in. He estimates the warehouse is 300 ft wide, 150 ft long, and 10 ft high.

Which expression should Jackson use in the process?