Average speed = Distance traveled / time taken
In jogging case Time taken = distance/speed
= 8.10/9.85 = 0.8223 hours
In care case Time taken = distance/speed
= 16.2/v hours
So total time taken , t = 0.8223+16.2/v
Total distance traveled = 8.10 km + 16.2 km = 24.30 km
So average speed [tex]= \frac{24.30}{0.8223+(16.2/v) } =21 km/hr[/tex]
[tex]v=48.38 km/hr[/tex]
Average speed you must drive your car if your average speed for the entire 24.3 km is to be 21.0 km/h = 48.38 km/hr
