At first glance, this visual puzzle looks deceptively simple, yet it has confused many people online. Four identical glasses appear to be filled to the same level with water, but each one contains a different submerged object. The challenge asks which glass actually contains the most water, and most viewers instinctively assume the answer can be found by simply comparing the water levels.
The puzzle shows four glasses labeled A, B, C, and D. Glass A contains a small paperclip, Glass B holds a large baseball, Glass C includes a rubber eraser, and Glass D contains a wristwatch. Because the water in each glass reaches the same height, it is easy to assume that all four contain equal amounts of water. However, this assumption is what makes the puzzle misleading, since it ignores how physical space is shared inside each glass.
The key to solving it lies in understanding displacement. When an object is placed in water, it takes up space and pushes an equal volume of water aside. The larger the object, the more water it displaces. In a container that is filled to the brim, any space occupied by an object reduces the amount of water the glass can actually hold.
Applying this principle reveals the solution. The baseball in Glass B displaces the most water, followed by the eraser and the wristwatch in Glasses C and D. The paperclip in Glass A displaces the least water because it is the smallest object. As a result, Glass A contains the greatest volume of actual water, even though all four glasses appear identical at first glance.
