There is a water proof tree house that is a hundred feet off the ground. Inside, there is a bath tub. You start filling the tub to take a bath. You try to adjust the temperature, and the handle falls off, so you can't shut the water off. You try the door and find out that it is jammed so you can't get out. Pretty soon, the water will fill the tree house, and either you will drown, or the tree house will burst, making you fall to your death. What do you do to survive?
Consider a vertical wheel of radius 10 cm. Now suppose a smaller wheel of radius 2 cm, is made to roll around the larger wheel in the same vertical plane while the larger wheel remains fixed. What is the total number of rotations the smaller wheel makes when its center makes one complete rotation about the larger wheel?