To go from diameter to radius, what do I need to do?

The volume of gas a balloon can hold varies directly as the cube of its radius. imagine a balloon with a radius of 3 inches can hold 81 cubic inches of gas. how many cubic inches of gas must be released to reduce the radius down to 2 inches?

Acourt reporter is transcribing an accident report from germany. the report states that the driver was traveling 80 kilometers per hour. how many miles per hour was the driver traveling?

Which of the following is the inverse of y = 3∧x y = 1/3∧x y = ㏒3x y = (1/3) ∧x y = ㏒ 1/3∧x