Math
posted by Anonymous .
A circular swimming pool is 4 feet deep and has a diameter of 15 feet. If it takes 7.5 gallons of water to fill one cubic foot, to the nearest whole number, how many gallons are needed to fill this swimming pool.
Diameter = 2r
A = π r^2
V = 4A
W = 7.5V

Plug in the values, starting with the first equation.
D = 2r, therefore D/2 = r
Put the value of r in the second equation to find A.
Put the value of A in the third equation to find V.
W = # of gallons = 7.5V
You can do the calculations.