Compare the speeds of the cyclist and the car for the entire journey.

Cyclist's Journey:

• The cyclist traveled 120 km from A to B.
• The cyclist reached point B at t=10 hours.
• Cyclist's speed = Distance / Time = 120 km / 10 hours = 12 km/h.

Car's Journey:

• The car traveled from A to B (120 km) and back to A (120 km), a total of 240 km.
• The car started at t=9 and returned to A at t=21. Total time = 21 - 9 = 12 hours.
• However, the car had a 2-hour stop. So, the actual travel time was 12 hours - 2 hours = 10 hours.
• Car's average speed = Total Distance / Actual Travel Time = 240 km / 10 hours = 24 km/h.

Comparison: The car's average speed (24 km/h) was twice the cyclist's speed (12 km/h).

Ответ: Средняя скорость автомобиля (24 км/ч) была в два раза выше средней скорости велосипедиста (12 км/ч).