If you picked Glass A, you got it right. Here’s why.

It’s all about space, not weight

The trick behind this puzzle is a simple science idea called water displacement. When you drop an object into water, it pushes the water out of the way and takes up that space for itself.

All four glasses are the same size and filled to the same line. So the glass with the smallest object has the most room left for water, and the glass with the biggest object has the least.

Ranked from most water to least:

1. Glass A (paperclip): tiny, so it barely takes up any space
2. Glass D (wristwatch) and Glass C (eraser): small, and close to each other depending on their size
3. Glass B (baseball): by far the biggest object, so it holds the least water

Why so many people get it wrong

There are two common mistakes:

• Looking only at the water line. The levels look the same, so people assume the amount of water is the same too. It isn’t.
• Thinking the heaviest object matters most. Weight doesn’t decide how much room an object takes up underwater. Size (volume) does. A small, heavy watch takes up much less space than a big, light baseball.

A fun twist most people miss ⚾

In real life, a baseball would actually float, because it’s lighter than the same amount of water. A floating object pushes aside only as much water as it weighs, so the baseball wouldn’t take up its full size in the glass.

Does that change the answer? No. Even floating, the baseball moves far more water than a tiny paperclip, so Glass A still wins.

What your answer “says about you”

Some versions of this puzzle claim your choice shows your personality. For example, picking the paperclip supposedly means you notice small details, and picking the baseball means you think about the big picture. It’s fun to talk about, but it isn’t real science.

The real lesson is simpler: things that look equal on the surface aren’t always equal underneath. Sometimes the smallest detail makes the biggest difference.

Did you get it right? Tell us in the comments! 👇