## Task 3 - 280513

Four equally sized boxes with the same contents have a combined mass of $132 \mathrm{~kg}$.

What is the mass of the contents of one box, if the total mass of all four empty boxes is 12 $\mathrm{kg}$?
Due to 132 - $12=120$, the total mass of the contents of the four boxes is $120 \mathrm{~kg}$. Consequently, due to $120: 4=30$, the mass of the contents of each box is $30 \mathrm{~kg}$.