Seven identical cylindrical chalk-sticks are fitted tightly in a cylindrical container. The figure below shows the arrangement of the chalk-sticks inside the cylinder.
The length of the container is equal to the length of the chalk-sticks. The ratio of the occupied space to the empty space of the container is
- $5 / 2$
- $7 / 2$
- $9 / 2$
- $3$
