1. [tex]d = \frac{m}{V} = \frac{20\ kg}{2\ m^3} = \bf 10\frac{kg}{m^3}[/tex]
2. [tex]d = \frac{m}{V} = \frac{0,45\ g}{140\ mL} = \bf 0,003\frac{g}{mL}[/tex]
3. [tex]d = \frac{m}{V} = \frac{0,9\ g}{450\ mL} = \bf 0,002\frac{g}{mL}[/tex]
4. [tex]d = \frac{m}{V}\ \to\ m = d\cdot V = 1,25\frac{g}{mL}\cdot 125\ mL = \bf 156,25\ g[/tex]
5. [tex]d = \frac{m}{V} = \frac{217,5\ g}{300\ mL} = \bf 0,725\frac{g}{mL}[/tex]