Two persons are to run a race, but one can run 10 meters per second, whereas the other can run 6 meters per second. If the slower runner has a 70-meter head start, how long will it be before the faster runner catches the slower runner, if they begin at the same time?

Answer 1

the speed difference is 4m/s
The distance difference is 70m.

so, the faster runner will take 70/4=17.5s to catch up