That’s why simply looking at the waterline can be misleading.
The Trick Behind the Puzzle
To solve the puzzle correctly, you need to pay attention to several details:
- The size of each glass
- The amount of water originally present
- The size of the object inside
- How much of the object is submerged
- Whether the glasses themselves are identical
The visual appearance can make one answer seem obvious, but the actual answer depends on the volume of water—not simply the height of the waterline.
Why These Puzzles Fool So Many People
Our brains naturally rely on quick visual judgments.
When we see a glass with a high water level, we tend to assume it must contain more water. We don’t automatically account for the space occupied by an object.
That’s what makes this type of puzzle so effective.
It tests whether you’re willing to slow down and examine the details instead of trusting your first impression.
A Simple Lesson in Physics
Although this is presented as a fun brain teaser, it demonstrates a real physical concept.
When an object is submerged in water, it displaces an amount of water corresponding to the volume of the submerged portion of the object.
