Question

A car drives 10km with a speed of 72 km/hr and then runs out of gas. Then you walk 2km for the next 30 min

until you find a gas station.

Answer 1

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 :

`v_(avg)=\frac{\text{Total distance covered}}{\text{Total time taken}}\\\\v_(avg)=(10+2)/((10)/(72)+(1)/(2))\\\\\\v_(avg)=18.78\ km/hr`

Hence , this is the required solution .