1/3 of the certain journals is covered at the rate of 25km/h, 1/4 at the rate of 30km/h and the rest of 50km/h. what is the avarage speed for the whole journey? About the author Amaya
average speed = (25/3+30/4+50)÷3
=(8.3+7.5+50)/3=65.8/3=32.47