What is the maximum permissible towed load behind a truck with a permissible total mass of 15 t (continuous brake system)?

You answered correctly. For trucks with a continuous brake system, German traffic law states that the maximum permissible towed load may be up to 1.5 times the permissible total mass of the towing vehicle. In this case, a truck with a total mass of 15 tons may tow a maximum of 22.5 tons (15 t x 1.5 = 22.5 t) if a continuous brake system is present on the trailer. This is a key rule to ensure safe braking ability when towing heavy loads. Always check the technical specifications and legal limits before towing.