You can put this solution on YOUR website! You drive to your Nana’s at a speed of 20 km/h and then come home at a speed to 30 km/h.
What is the average speed for the whole trip?
:
Let a = average speed for the whole trip
:
let d = distance one way
then
2d = distance for the whole trip
:
write a time equation; time = dist/speed
:
there time + return time = total time + =
multiply by 60a
60a* + 60a* = 60a
cancel the denominator, results:
3ad + 2ad = 60(2d)
5ad = 120d
Divide both side by d
5a = 120
a = 120/5
a = 24 mph average speed for the whole trip
