Volume and surface area of solids

A cone-shaped container has a radius of 9 cm and a height of 30 cm. It is filled with water to a height of 18 cm. Using the volume formula for a cone, calculate the volume of water in the container, giving your answer in litres, correct to 3 significant figures.
(Take the volume of a cone as $\frac{1}{3}\pi r^2h$.)