A motorist averages 48km/h for the first 30km of a journey and 64km/h for the next 120km. What is the average speed for the whole journey
To find the average speed for the whole journey, we need to first calculate the total distance traveled and the total time taken for the journey.
For the first 30km at 48km/h, the time taken is 30km / 48km/h = 0.625 hours.
For the next 120km at 64km/h, the time taken is 120km / 64km/h = 1.875 hours.
The total distance traveled is 30km + 120km = 150km.
The total time taken for the journey is 0.625 hours + 1.875 hours = 2.5 hours.
Therefore, the average speed for the whole journey is 150km / 2.5 hours = 60km/h.
So, the average speed for the whole journey is 60km/h.