Karl is racing against Frank. The race is run over a distance of 800 m. In the first race, Karl allows Frank to start 5 seconds before him, but still completes the race 3 seconds before Frank. In the second race, they start to run at the same time, but Karl allows Frank to start 100 m ahead of him on the track, so Frank only has to run 700 m. Frank completes this race 4.5 seconds before Karl. In the third race, they again start to run at the same time and Karl allows Frank to start 40 m ahead on the track. Karl runs each race at the same constant speed. Frank runs slower but at the same constant speed for each race.