A 15 cubic-foot aquarium is advertised as 2 feet tall and 3 feet wide. How deep is it?

15 / 6 = 2.5 feet

To find the depth of the aquarium, we can use the formula for volume:

Volume = Length × Width × Height

Given that the volume is 15 cubic feet, the height is 2 feet, and the width is 3 feet, we can substitute these values into the formula:

15 = Length × 3 × 2

To isolate the length, divide both sides by (3 × 2):

15 ÷ (3 × 2) = Length

Simplifying this expression:

15 ÷ 6 = Length

Length = 2.5

Therefore, the depth of the aquarium is 2.5 feet.