Think you have a sharp mind and a good eye for detail? Here’s a fun optical illusion that will truly put your brain to the test. At first, it looks like a simple number puzzle—but don’t be fooled! Although it may seem easy, only one in five people manage to get the correct answer in under a minute. And here’s the real challenge: can you crack it in just 15 seconds?
This tricky puzzle, created by UK-based game site Tombola, is more than just a brain teaser—it’s a way to test your pattern recognition skills, logic, and how quickly your brain can process information.
Your job is to find the correct number that completes the sequence. Sounds simple, right?
But don’t rush. Studies show that on average, it takes people around three minutes to solve this puzzle. Even more surprising? Two out of five people either get the answer completely wrong or simply give up halfway. That’s why solving it in 15 seconds is considered a sign of a truly quick-thinking mind.

Image Credit: Tombola
Why this puzzle is so toughSo, what makes this illusion so difficult? It’s not about how good your eyesight is—it’s about how fast your brain can recognize hidden patterns. The numbers might follow a logical order, but that logic isn’t always obvious at first glance.
Some people see it right away, while others stare at the image for minutes without any clue.
This puzzle challenges both short-term and long-term memory. According to brain experts, solving pattern-based illusions like this one can actually help improve your brain health. When your brain is pushed to recognize sequences, compare information, and eliminate wrong answers, it forms new neural connections—which is great for mental agility.
Take the challenge: Can you solve it?Ready to try it for yourself? Set a timer for 15 seconds, take a deep breath, and look at the puzzle. Focus, but don’t overthink it. Your brain might surprise you with how quickly it can spot the right answer.
Still stuck? Don’t worry!If you’re finding it difficult, you’re not alone. As mentioned earlier, the majority of people either answer incorrectly or need more than a minute to figure it out. It’s not about being "smart"—sometimes it just takes a fresh perspective or a different approach.
So, are you ready for the answer?Scroll down to reveal it…

Image Credit: Tombola
Why you should try more of these
Brainteasers like this aren’t just fun—they’re also good for your brain. Regularly challenging yourself with puzzles, illusions, and logic games has been shown to:
- Improve memory
- Sharpen concentration
- Boost problem-solving skills
- Delay age-related cognitive decline
So next time you’re scrolling through your phone or taking a break at work, try solving a quick puzzle like this one. You’ll be training your brain—and having fun while doing it!