KöMaL 2023 K756

A shop sells wooden cubes in two sizes: cubes of edge 1 cm and those with edges of 2 cm. The surfaces of the cubes are painted. In the case of the smaller cubes the paint represents 60% of the material costs, while the rest is the price of the wood. Both kinds of cube are made of the same type of wood and they are coated with a thin layer of paint with the same thickness. Labour costs are the same for each cube, independent of the size. Considering all costs, it costs the shop 830 forints (HUF, Hungarian currency) to manufacture 10 small cubes and 5 large ones. 5 small cubes and 15 large ones cost 1490 forints to manufacture. What is the labour cost of one cube?