How fast must a car travel to overtake a bus in 5 hours if the bus is averaging 30 kilometers per hour and left 3 hours before the car?

If the car must overtake the bus in 5 hours and the bus left 3 hours before the car, then the bus has traveled for 8 hours = 240 km.

The car needs an average speed of 240km / 5hr = 48 km/hr.