- Density can be calculated by measuring the mass of an object divided by the volume of that object
- A graduated cylinder is used to measure volume
- A balance is used to measure mass
- Therefore, the density of an object can be measured using a graduated cylinder and a balance

- The density of an object can be measured using a graduated cylinder and a balance
- A rock sample is a kind of object
- So, the density of a rock sample can be measured using a graduated cylinder and a balance

So, the density of a rock sample can be measured using a graduated cylinder and a balance
Which of the following would be most useful for calculating the density of a rock sample?
- Density can be calculated by measuring the mass of an object divided by the volume of that object 
- A rock sample is a kind of object 
- A graduated cylinder is used to measure volume 
- A balance is used to measure mass