What is the formula used to calculate the number of gallons of water in a swimming pool?

The correct formula to calculate the number of gallons of water in a swimming pool involves multiplying the length, width, and depth of the pool, and then applying a conversion factor to convert the cubic feet to gallons. Specifically, one cubic foot of water equals approximately 7.5 gallons. Therefore, when you multiply the length, width, and depth (which gives you the volume in cubic feet) by 7.5, you are accurately converting that volume into gallons. This is essential for determining how much water the pool can hold, which is important for maintenance, chemical balancing, and filling requirements.

The other options do not use the appropriate conversion factor or use incorrect dimensions for volume calculations, making them unsuitable for calculating the water volume in gallons.