Virginia beach is about 20 miles wide and 28 miles long. if one inch of rain falls there during a daily rain shower, how many cubic feet of rain fell? (convert all units to feet first)

In this question, you are given the width( 20 miles), the length(28 miles) and the height( 1 inch). You are asked to count the rain water volume which was going with formula length x width x height. But the unit asked is ft, so you need to convert them all. The calculation would be:

Water volume= length x width x height
Water volume= 20 miles x 5280ft/miles x 28 miles x 5280ft/miles x 1inch x 1ft/12inch
Water volume = 1300992000 cubic ft.

As we know 1 miles = 5280 feet.
Firstly we will convert everything into feet.

So Length = 28 miles =  28 * 5280 feet = 147,840 feet

Width = 20 miles = 20 * 5280 feet = 105,600 feet.

Depth = 1 inch=  1 * 1/12 feet = 1/12 feet
(because 1 inch = 1/12 feet)

So Volume = Length * Width * Depth
                   = 147840 * 105600 * 1/12 = 1300,992,000 cubic feet.

So we can say 1300,992,000 cubic feet rain fell.