Optimisation size garbage - Lycée Notre Dame du Grandchamp (Versailles)

Lycée Notre Dame du Grandchamp (Versailles)
A family has three garbage bins: blue (recyclables), green (compost), and black (others). At the beginning of the first week, all the bins are empty. Each week, the family generates a total of 10kg of waste. The waste is then sorted and placed in the bins. Then the heaviest bin is emptied, and its contents are thrown away. What is the minimum requirement (in kg) of each bin so that it does not overflow?