Question 6
Four cyclists start riding at exactly 12:00 noon. Each cyclist rides on a different circular track, where each track is exactly 1 mile long. The four cyclists ride at four different constant speeds, which are 6, 9, 12 and 15 miles per hour, respectively. All four tracks meet at the center (Point $A$). They all start together at the center and keep riding around their own track. They agree to stop when they have come back to the center together for the sixth time (counting the start at 12:00 noon as the first time). At what time do they stop?
Give the hour, minute, second and AM/PM.
Give the hour, minute, second and AM/PM.