To find the average speed of the car, you can use the formula:
\[ \text{Average Speed} = \frac{\text{Total Distance}}{\text{Total Time}} \]
In this case, the total distance is 180 kilometers and the total time is 3 hours.
\[ \text{Average Speed} = \frac{180 \text{ km}}{3 \text{ hours}} = 60 \text{ km/h} \]
Therefore, the average speed of the car was 60 kilometers per hour.