Vi vet at $220 \, \mathrm{mL}$ koster $22 \, \mathrm{kr}$.

Først finner vi prisen per milliliter:

$$\frac{22 \, \mathrm{kr}}{220 \, \mathrm{mL}} = 0{,}1 \, \mathrm{kr/mL}$$

Siden det er $1000 \, \mathrm{mL}$ i én liter, ganger vi med $1000$:

$$0{,}1 \, \mathrm{kr/mL} \cdot 1000 \, \mathrm{mL/L} = \mathbf{100 \, \mathrm{kr/L}}$$

Cappuccinoen koster $\underline{\underline{100 \, \mathrm{kr}}}$ per liter.