Final answer:
The total mass of the system, consisting of the painter and the chair, is 84 kg.
Step-by-step explanation:
The question relates to a scenario where a house painter uses a chair and pulley system to lift themselves up the side of a house. To determine the total mass of the system, we simply add the mass of the painter and the mass of the chair. Given that the painter's mass is 75 kg and the chair's mass is 9.0 kg, we calculate the total mass by summing these values: 75 kg + 9.0 kg = 84 kg. Therefore, the total mass of the system is 84 kg.