Final answer:
The force exerted by each cable on the platform is 466 N.
Step-by-step explanation:
To find the force exerted by each cable on the platform, we need to consider the vertical forces acting on the system. The weight of the painter and the weight of the platform both act downwards, so the total weight of the system is (75 kg + 20.0 kg) * 9.8 m/s² = 931 N. Since the platform is held in equilibrium, the vertical forces on each end of the platform must balance out. This means that the force exerted by the left-hand cable is equal to half the total weight of the system, which is 931 N / 2 = 466 N. Similarly, the force exerted by the right-hand cable is also 466 N.