Given :
A car drives 10 km with a speed of 72 km/hr and then runs out of gas.
Then you walk 2 km for the next 30 min until you find a gas station .
To Find :
The average speed of whole journey .
Solution :
Average speed is given by :
[tex]v_{avg}=\dfrac{\text{Total distance covered}}{\text{Total time taken}}\\\\v_{avg}=\dfrac{10+2}{\dfrac{10}{72}+\dfrac{1}{2}}\\\\\\v_{avg}=18.78\ km/hr[/tex]
Hence , this is the required solution .
