The diagram shows a container for grain.

The container is a cylinder on top of a cone. The cylinder has a radius of 3 m and a height of m. The cone has a base radius of 3 m and a vertical height of 4 m.
The container is empty. The container is then filled with grain at a constant rate.
After 5 hours the depth of the grain is 6 metres above the vertex of the cone. After 9 hours the container is full of grain.
Work out the value of . Give your answer as a fraction in its simplest form. You must show all your working.






























































