|Nose to Nose|
It is one of the weekly puzzles.
Four horses running around a course made up of several concentric circles.
Horse A runs one lap an hour on it's course.
Horse B runs two laps an hour on it's course.
Horse C runs three laps an hour on it's course.
Horse D runs four laps an hour on it's course.
All four horses line up at the bottom of the circle and start running their courses at the same time. How many minutes will it take until all four horses are lined up nose to nose on a straight line again.