43+ Best TED Ed Riddles to Challenge Your Thinking

A king has 1,000 bottles of wine, one of which is poisoned. He has 10 prisoners to test the wine. How can he identify the poisoned bottle in the fewest tests? 🤔

You cut a chocolate bar into pieces and rearrange them, seemingly creating extra chocolate. How is this possible? 🤔

You have two ropes that burn unevenly but take exactly 60 minutes to burn completely. How can you measure exactly 45 minutes? 🤔

You have a 5-liter jug and a 3-liter jug. How can you measure exactly 4 liters of water? 🤔

A king offers a reward: one grain of rice on the first square of a chessboard, two on the second, four on the third, and so on. How many grains are on the 64th square? 🤔

You’re in a room with three light switches outside. Only one controls a bulb inside the room. You can’t see the bulb from outside. How can you determine which switch controls the bulb with only one trip into the room? 🤔

If a monkey randomly types on a keyboard for an infinite amount of time, what’s the probability it will type the complete works of Shakespeare? 🤔

Three gods—True, False, and Random—must be identified by asking yes/no questions. True always tells the truth, False always lies, and Random answers randomly. How can you determine which god is which in three questions? 🤔

Four prisoners are given hats—two black and two white. They can’t see their own hat but can see the others’. They must guess their own hat color without communicating. How can they ensure at least one correct guess? 🤔

Two trains are 100 miles apart, heading toward each other at 50 mph each. A bird flies back and forth between them at 75 mph until the trains meet. How far does the bird fly? 🤔

Three ants are on the corners of an equilateral triangle. Each ant randomly chooses a direction and moves along the edge. What’s the probability they won’t collide? 🤔

In a town, the barber shaves all and only those who do not shave themselves. Who shaves the barber? 🤔

You’re faced with two doors. One leads to candy, the other to broccoli. Two guards stand by the doors—one always lies, the other always tells the truth. You can ask one guard one question to find the candy door. What do you ask? 🤔

Three friends share 12 cookies. Each friend gets 4 cookies, but there’s still one cookie left. How is this possible? 🤔

You have a 5-liter jug and a 3-liter jug. How can you measure exactly 4 liters of magic potion? 🤔

A farmer needs to take a wolf, a goat, and a cabbage across a river. His boat can only carry one thing at a time. If he leaves the wolf and goat alone, the wolf will eat the goat. If he leaves the goat and cabbage alone, the goat will eat the cabbage. How can he get everything across safely? 🤔

I appear after the rain, with colors so bright. I’m an arc in the sky, a magical sight. What am I? 🤔

I’m not a star, but I shine at night. I’m not the sun, but I reflect its light. What am I? 🤔

I grow tall and strong, with leaves so green. Birds build nests in me, and I’m often seen. What am I? 🤔

I start as a caterpillar, then take a long nap. When I wake up, I’m a colorful flap. What am I? 🤔

I flow and I twist, but I never walk. I have a bed, but I never sleep. What am I? 🤔

I follow you everywhere but never say a word. I’m tall in the morning but short in the afternoon. What am I? 🤔

A hotel has an infinite number of rooms, all occupied. A new guest arrives. How can the hotel accommodate them without evicting anyone? 🤔

Three friends pay $10 each for a $30 hotel room. Later, the clerk realizes the room costs only $25 and gives $5 to the bellboy to return. The bellboy keeps $2 and gives $1 back to each friend. Now, each friend paid $9, totaling $27, and the bellboy has $2. Where’s the missing dollar? 🤔

You’re on a game show with three doors. Behind one is a car, and behind the others are goats. You pick a door, and the host opens another door revealing a goat. Should you switch your choice to the remaining door? 🤔

A king offers a reward: one grain of rice on the first square of a chessboard, two on the second, four on the third, and so on. How many grains are on the 64th square? 🤔

You’re given two envelopes, one with twice as much money as the other. You pick one and find $100. Should you switch to the other envelope? 🤔

Five pirates must divide 100 gold coins. The most senior pirate proposes a distribution, and all pirates vote. If the proposal gets at least half the votes, it passes. Otherwise, the proposer is thrown overboard. How should the coins be divided to maximize the senior pirate’s share? 🤔

You have two ropes that burn unevenly but take exactly 60 minutes to burn completely. How can you measure exactly 45 minutes? 🤔

You have a 5-liter jug and a 3-liter jug. How can you measure exactly 4 liters of water? 🤔

If a monkey randomly types on a keyboard for an infinite amount of time, what’s the probability it will type the complete works of Shakespeare? 🤔

In a town, the barber shaves all and only those who do not shave themselves. Who shaves the barber? 🤔

I show you what you are, but I’m not a camera. I’m not alive, but I can reflect life. What am I? 🤔

I can be given, but not held. I can be shared, but not seen. What am I? 🤔

I’m always in front of you but can’t be seen. I’m always behind you but can’t be touched. What am I? 🤔

I have words but never speak. I have knowledge but never learn. What am I? 🤔

I’m always with you, but you can’t catch me. I’m darkest at noon but disappear at night. What am I? 🤔

I can knock down trees, but I’m not a lumberjack. I can carry a kite, but I’m not a string. What am I? 🤔

I can open doors, but I’m not a key. I can start a story, but I’m not a word. What am I? 🤔

I connect two places but can’t be seen. I’m built with words but not with bricks. What am I? 🤔

I make music without a voice. I can be heard but not seen. What am I? 🤔

I have no beginning or end, but I connect everything. I’m not a road, but I guide you. What am I? 🤔