Atrain travels 68 km at an average speed of 51 km/h. it then travels another 20 km at an average speed of 40 km/h before reaching its destination. calculate the average speed for the whole journey. also give the solution of this problem.

time = distance / rate

travelling 68 km at 51 km/hour = 1 + (1/3) hours

travelling 20 km at 40 km/hour = .50 hours

total time = 1.8333333... hours

total distance = 68 + 20 = 88 kilometers

average speed = 88 km / 1.8333333... hours

average speed = 48 km / hour

5050

hope this !