Felix and Markus want to drive a 60km long route in a maximum of 3 hours. After 40 minutes you do the first time check. How long do you actually need to cover the 60km?
to do the whole trip in 3 hours, you need a speed of 20 km/hr
But I have no idea how far along the road you are after 40 minutes.
40min = 2/9 of 3 hours, so you need to be at least 13.33 km along your way if you want to finish in time at your speed.