The maximum speed of a train is 90 km/h. It takes 10 hours to cover a distance of 500 km. Find the ratio of its average speed to maximum speed?

Here, maximum speed $v_m=90\ km/h$

As given, the train takes $10$ hours to cover a distance of $500\ km$

Therefore, the average speed $v_a=\frac{500\ km}{10\ hour}=50\ km/h$

So, the ratio of the average speed to maximum speed $=v_a:v_m$

$=50\ km/h:90\ km/h$

$=5:9$