Two cars moves around a circle of circumference 20 m with speed of 5m/s and 15m/s, if the positions of these cars are observed every integer seconds, after how many seconds will the cars occupy the same position.

Help me show step

the time for meeting is the time one has traveled distance d and the faster has traveled d+20

distance slower travels: d=5t
distance faster travels: d+20=15t

5t+20=15t
t=2 seconds, the slower car is halfway round, and the faster car has made it 1.5 around.