Eurekat: Brain Teasers

Questions where your gut gets it wrong. Then one new way of seeing it makes the answer obvious, and teaches you an idea you’ll spot everywhere.

Eurekat gives you one good question a day across math, probability, logic, physics, chemistry and coding. No typing, no timers, no grades. Just you, one good question and the moment it clicks.

WATCH IT CLICK
We don’t animate for decoration. We animate the exact moment the answer becomes obvious. Many questions come with a little game: try it, get stuck, and feel why the trick matters.

EVERY ANSWER IS EARNED
Every answer is proven, simulated or run as code. Play Monty Hall 10,000 times and watch switching settle at two in three.

MANY KINDS OF QUESTION
• Classic puzzles and paradoxes
• Spot the flaw in a convincing proof
• Which is bigger? Estimate. Predict.
• Visual proofs you can see at a glance
• Debates where the experts still disagree

MAKE IT A HABIT
• A gentle reminder each morning
• A streak to keep
• Hints when you’re stuck, and a gut-check before you reveal
• Save favourites, synced across phone and web
• Read and vote on other people’s solutions, or write your own

FREE TO PLAY
Today’s question is always free, and no account is needed to play. Sign in for free archive questions every week.

EUREKAT CLUB (optional)
Open every question in the archive, all Pro tracks and the hard tier. Yearly with a 7-day free trial, or monthly. Works in the app and on eurekat.app.

Payment is charged to your Google Play account. The subscription renews automatically until you cancel; manage or cancel any time in Play Store → Payments & subscriptions.

Terms: https://eurekat.app/terms
Privacy: https://eurekat.app/privacy