Subject: math
Name: jon
Who are you: Other (All)

what would be the formula to fill a swimming pool in with dirt that is 15ft wide,36ft long and is 8ft deep to 3ft deep


Hi Jon,

I am going to assume that you want the volume of dirt required in cubic yards. The volume expression is

length x width x average depth

but to obtain the volume in cubic yards you need to express the dimensions in yards not feet. There are 3 feet in a yard so

15 feet = 15/3 = 5 yards and
 36 feet = 36/3 = 12 yards

If the depth slopes gradually from 3 feet to 8 feet then the average depth is 
(3 + 8)/2  = 5.5 feet. Thus the average depth in yards is

5.5 feet = 5.5/3 = 1.83 yards

Hence the volume of dirt required is

5 x 12 x 1.83 = 110 cubic yards.