Jamina drove for 2 hours at an average speed of 40km/h. She then drove for 3 hours at an average speed of 50km/h. What was her average speed for the whole journey?

Remark

Average Speed = Total distance divided by total time.

Total Time

2 hours + 3 hours = 5 hours. The total time is 5 hours.

Total Distance

d = rate * time

d1 = 40 km/hour * 2 hours = 80 km

d2 = 50 km/hour * 3 hours = 150 km

d = d1 + d2

d = 80 + 150 = 230 km

Average Speed

Av = Total distance / Total Time = 230 / 5 = 46 km/hr