A train covers 40km between two stations in 45 minutes. It covers another 30km in 30 minutes and the remaining 20km in 15 minutes. Find the average speed of the train in the whole journey.
- A40km/h
- B60km/h
- C50km/h
- D45km/h
Solution & Step-by-step Explanation
The formula for average speed is:
Average Speed=
Total Time
Total Distance
Total Distance=40km+30km+20km=90km
Total Time=45minutes+30minutes+15minutes=90minutes
Convert total time into hours:
90minutes=
60
90
hours=1.5hours
Now, calculate the average speed:
Average Speed=
1.5hours
90km
=60km/h
Therefore, the average speed of the train is 60km/h.
Average Speed=
Total Time
Total Distance
Total Distance=40km+30km+20km=90km
Total Time=45minutes+30minutes+15minutes=90minutes
Convert total time into hours:
90minutes=
60
90
hours=1.5hours
Now, calculate the average speed:
Average Speed=
1.5hours
90km
=60km/h
Therefore, the average speed of the train is 60km/h.