80. Two suitcases. A gentleman needed to get to a railway station located 4 km from his house. His luggage consisted of two equally heavy suitcases, which he could not carry alone. The gardener and the servant insisted that they should be entrusted with carrying the luggage. However, the gardener was too old, and the servant was too weak. The gentleman insisted that each should take an equal part in carrying the luggage, and he was unwilling to give up his right to carry the suitcases for his share of the journey.

The gardener and the servant took one suitcase each, while the gentleman, walking light, thought about how he should act so that all three of them expended equal effort.

So how should he
80. The servant must carry a suitcase \(1 \frac{1}{3}\) km and hand it over to the gentleman, who will carry the suitcase to the station. The gardener must carry another suitcase \(2 \frac{2}{3}\) km, and then hand it over to the servant, who will carry the suitcase to the station. Thus, each of them will carry one suitcase \(2 \frac{2}{3}\) km - in other words, the effort spent on carrying the luggage by the gentleman, the servant, and the gardener will be the same.