A person travels 600 km by train at 80 km/hr and 100 km by car at 50 km/hr. What is the average speed for the entire distance?
average speed =(total distance traveled)(total time taken)
Given: first 600km traveled with 80km/hr speed and next 100km traveled with 50km/hr speed.
therefore total distance=700km
total time taken =60080+10050=9.5hours
so average speed =7009.5=73.6842105 km/hr