The Average velocity which is needed to qualify for the race : 200 km/h.
Let the distance for each lap be
The Total distance is =
then total time taken to finish the race at average velocity 200km/h is =
If average velocity decraeses to 170 km/h,
then Total time taken to cover two laps =
Remaining time to finish and qualify for the race is =
So the average velocity to complete and qualify for the race is =