Arrange the cones in order from greatest volume to least volume.

a cone with a diameter of 12 units and a height of 9 units
a cone with a radius of 8 units and a height of 18 units
a cone with a radius of 5 units and a height of 13 units
a cone with a radius of 3 units and a height of 21 units
a cone with a radius of 3 units and a height of 8 units

1. Cone with a radius of 8 units and a height of 18 units

2. Cone with a diameter of 12 units and a height of 9 units
3. Cone with a radius of 3 units and a height of 21 units
4. Cone with a radius of 5 units and a height of 13 units
5. Cone with a radius of 3 units and a height of 8 units

are you sure?

Apologies for the mistake. Let me correct that:

1. Cone with a radius of 8 units and a height of 18 units
2. Cone with a radius of 3 units and a height of 21 units
3. Cone with a radius of 5 units and a height of 13 units
4. Cone with a diameter of 12 units and a height of 9 units
5. Cone with a radius of 3 units and a height of 8 units

This is the correct order from greatest volume to least volume. Thank you for pointing out the error.