100+ Brainteasers with answers for kids and adults

Brainteasers with Answers - "Challenge your brain and improve your problem-solving skills with our collection of brainteasers. From logic puzzles to wordplay, our brainteasers will keep you entertained and engaged for hours. Whether you're a student looking to boost your grades or an adult looking to keep your mind sharp, our brainteasers have something for everyone. Test your mental aptitude and see just how clever you are with our challenging and fun collection of brainteasers."

The Speeding Train-Brain teaser

16. Riddles
A train 1 mile long is traveling at a speed of 1 mile per minute through a tunnel 1 mile long. How long will it take for the train to completely pass through the tunnel?

    • It will take 2 minutes. The front of the train takes 1 minute to exit the tunnel, but the back still needs another minute to completely pass through.

The Chessboard Puzzle-Brain teaser

17. Riddles
A chessboard has 64 squares. If you remove two opposite corner squares, can you cover the remaining 62 squares with 31 dominoes, each covering exactly 2 squares?
    • No, you can. Each domino covers two adjacent squares of different colors, but removing two opposite corners removes two squares of the same color. This leaves an odd number of squares of each color, making it impossible to cover them evenly with dominoes.

The Boat and the Plank-Brain teaser

18. Riddles
A boat is floating in the water, and a heavy plank of wood is on the boat. If the plank is thrown overboard into the water, what will happen to the water level?

    • The water level will drop. When the plank is on the boat, it displaces a volume of water equivalent to the weight of the plank. When it's in the water, it displaces only a volume equal to its own volume, which is less than the volume displaced by its weight.

The Water and Wine Puzzle-brain teaserhaa

19. Riddles
You have two glasses, one filled with water and the other filled with wine. You take a spoonful of water and pour it into the wine glass, then take a spoonful of the wine-water mixture and pour it back into the water glass. Is there more water in the wine or more wine in the water?

    • The amounts of water in the wine and wine in the water are the same. The process of mixing and exchanging liquids balances out the quantities.

The Magic Number

20. Riddles
Pick any number. Double it. Add 9. Subtract 3. Divide by 2. Subtract the original number. What number are you left with?

    • The number is always 3, regardless of the original number you picked.

The Unbreakable Rope-Brain teaser

22. Riddles
You have a rope that burns in exactly 30 minutes. The rope doesn't burn at a uniform rate. How can you measure exactly 15 minutes using this rope?

    • Light the rope from both ends. When the flames meet, exactly 15 minutes will have passed.

The River Crossing-Brain teaser

24. Riddles
You have a fox, a chicken, and a sack of grain. You need to get all three across a river using a boat that can only carry one at a time. If you leave the fox with the chicken, the fox will eat the chicken. If you leave the chicken with the grain, the chicken will eat the grain. How can you get all three across the river safely?

    • 1. Take the chicken across the river.
2. Go back and take the fox across the river.
3. Take the chicken back to the original side.
4. Take the grain across the river.
5. Finally, go back and bring the chicken across.

The Missing Dollar-Brain teaser

25. Riddles
Three friends check into a hotel room that costs $30. They each contribute $10 and pay the bill. Later, the hotel realizes they made a mistake and the room only costs $25. The bellboy is sent to return $5 to the friends. Unsure how to split the $5, the bellboy decides to give each friend $1 and keep $2 as a tip. Now, each friend has paid $9 (totaling $27), and the bellboy kept $2, which sums up to $29. Where is the missing dollar?

    • There is no missing dollar. The mistake lies in the way the total is calculated. The $27 already includes the $2 that the bellboy took. So, $25 went to the hotel, and $2 went to the bellboy.

Four cars and-Four Way- Brain Teasers

26. Riddles
Four cars come to a four-way stop, all coming from a different direction. They can't decide who got there first, so they all go forward at the same time. They do not crash into each other, but all four cars go. How is this possible?
    • Answer: They all made right-hand turns

Rabbit Run-Brain Teasers

27. Riddles
How far can a rabbit run into the woods?
    • Answer:-Halfway. After that, he is running out of the woods.

The Light Switches-Brain teaser

28. Riddles
You are in a room with three light switches. Each switch controls one of the three light bulbs in the next room. You can flip the switches as many times as you like, but you can only go into the next room once. How do you determine which switch controls which bulb?

    • Turn on the first switch and leave it on for a few minutes.
2. Turn it off and immediately turn on the second switch.
3. Go into the next room:
   - The bulb that is on is controlled by the second switch.
   - The bulb that is warm but off is controlled by the first switch.
   - The bulb that is cold and off is controlled by the third switch.

Two coins-Brain Teasers

29. Riddles
In my hand I have two coins that are newly minted. Together, they total 30 cents. One isn't a nickel. What are the coins? 
    • Answer: A quarter and a nickel

The Crossing Bridge-brain teaser

30. Riddles
Four people need to cross a bridge at night. They only have one torch, and the bridge is too dangerous to cross without it. The bridge can only hold two people at a time. The four people take different times to cross: 1 minute, 2 minutes, 7 minutes, and 10 minutes. How do they all get across in the shortest time possible?

    • 1. The 1-minute and 2-minute people cross first with the torch (2 minutes).
2. The 1-minute person goes back with the torch (1 minute).
3. The 7-minute and 10-minute people cross with the torch (10 minutes).
4. The 2-minute person goes back with the torch (2 minutes).
5. The 1-minute and 2-minute people cross again (2 minutes).
Total time: 17 minutes.