The winning car in a Grand Prix race covers the \(\quantity{360}{km}\) course at an average speed of \(\quantity{150}{km/h}\). The second car takes \(6\) minutes longer than the first. Find the average speed of the second car.
As the first car has an average speed of \(\quantity{150}{km/h}\), it needs \[\frac{\quantity{360}{km}}{\quantity{150}{km/h}} = \quantity{2.4}{h}\] for the whole course.
Now the second car takes \(\quantity{6}{min} = \quantity{0.1}{h}\) longer than the first car. Hence it needs \(\quantity{2.5}{h}\) for the full course. This makes for an average speed of \[\frac{\quantity{360}{km}}{\quantity{2.5}{h}} = \quantity{144}{km/h}.\]
