For a cone, the formula r = 3V divided by rh( all enclosed in square root symbol) describes the relationship between the radius r of the base, the volume V, and the height h. Solve the formula for V.

That's really not a "story" problem. They tell you a formula to start with.

Also, you have written the formula incorrectly

Actually, r = sqrt[3V/(pi*h)]
You replaced a "pi" symbol with an r.

Square both sides and multiply by (pi*h/3) to get a formula for V alone