What is the amount of water in a pond 3 ft deep and 1 mile around?

To calculate the amount of water in a cylindrical pond, you need to know the volume of the cylinder and the density of water.

The formula for the volume of a cylinder is V = πr^2h, where V is the volume, r is the radius, and h is the height.

We can convert 1 mile to feet by multiplying by 5280, so the pond has a radius of 5280 / 2 = 2640 feet.

Plugging in the values we know, we get V = π * 2640^2 * 3 = 2.24 x 10^10 cubic feet.

The density of water at room temperature is about 62.4 pounds per cubic foot. So the total weight of the water in the pond is 62.4 * 2.24 x 10^10 = 1.39 x 10^12 pounds.

To convert this to gallons, we need to divide by the weight of 1 gallon of water, which is about 8.34 pounds. So the amount of water in the pond is 1.39 x 10^12 pounds / 8.34 pounds per gallon = 1.67 x 10^11 gallons.

So the pond contains approximately 1.67 x 10^11 gallons of water.