Most people immediately judge the puzzle based on water level alone. Since all four glasses appear equally full, the brain instinctively assumes the amount of water must be roughly the same.

That’s where the trick comes in.

The key to solving the puzzle is understanding displacement.

Every object placed inside the glass takes up space. The larger the object, the less room remains available for actual water.

That means the correct answer is Glass A.

Because the paperclip is the smallest object, it displaces the least amount of water. In other words, Glass A contains more real water than the others, even though the surface levels appear similar.

Meanwhile, the baseball in Glass B takes up a huge amount of space, meaning there’s actually far less water inside despite what your eyes initially suggest.

It’s a simple scientific principle — but one that easily tricks the brain.

And that’s exactly why puzzles like this spread so quickly online.

Continued on the next page