contestada

7. A car travels a certain distance with a speed of
50 km/h and returns with a speed of 40 km/h.
Calculate the average speed
Plz help

Respuesta :

Let distance be x.

Time in going, t 1 = x/50

Time in coming, t 2 = x/40

Total time T = x/40 +x/50 = 9x/200

Average speed = total distance/ total time

=( x+x)/(9x/200)= 2x ×200/9x = 400/9 = 44.44 km/h