Ihave trouble figuring out these questions

1. a metal ball has a mass of 2kg and a volume of 6m to the third power. what is its density?

2. a certain gas expands to fill a 3l container. its madd is measures to be 0.6 kg what is the density?

3. a solid is 5cm tall, 3 cm wide and 2 cm thick it has a mass of 129g. what is its density?

4. in terms of volume, how do ml and cm to the third power relate to one another?

5. a graduated cylinder is filled to an initial volume of 12.7 ml. a rock is dropped into the graduated cylinder. the final volume of the graduated cylinder is 18.2 ml what is the rocks volume?
what method was used to determine this?