The Golden Cylinder
You are shown two cylinders – one of them is made of gold and hollow, the other one is made of alloy and solid. Both of them have the same weight, shape, and are colored in black. How can you figure out which cylinder is the golden one, without scratching the paint?
SOLUTION
Simply roll the two cylinders on the ground. The hollow one will roll farther than the solid one
We do not know where this puzzle originated from. If you have any information, please let us know via email.