Put in your 2-cents worth -It's all in the penny-Geometry Level pending
A penny rotates about a stationary quarter. The penny never loses contact with the quarter and does not slip in its rotation. The radius of the quarter is 5/4 that of the penny.
The penny rotates from point A on the quarter until it contacts the same point again. How many revolutions does the penny make in the time that it travels around the quarter?
Hint: Try to measure the number of revolutions a quarter would make if it rotated around a stationary quarter. (Do this physically)