Puzzles aren’t just fun brain teasers; they’re a vital part of interview preparation. Whether you’re applying for roles at Google, Microsoft, or Amazon, or preparing for exams like CAT, UPSC, and SSC, logic puzzles test your ability to think clearly under pressure. These puzzles reveal how you handle problems, find patterns, and stay calm when solutions aren’t obvious. Interviewers use them to test reasoning ability, problem-solving skills, and presence of mind.
To help you prepare, here’s a list of the Top 25 Puzzles Asked in Interviews, complete with short explanations you can easily remember and share.
Puzzles for Interviews and Exams
| No. | Puzzle | Description |
|---|---|---|
| 1 | The River Crossing Puzzle | A farmer needs to transport a wolf, a goat, and a cabbage across a river. He has a boat that can carry only him and one other item at a time. How can he do it without leaving the wolf alone with the goat or the goat alone with the cabbage? |
| 2 | The Two Jug Problem | You have a 3-liter jug and a 5-liter jug. How can you measure exactly 4 liters of water using these two jugs? |
| 3 | The Missing Dollar Riddle | Three people check into a hotel room that costs $30. They each contribute $10. Later, the hotel realizes the room was only $25 and gives $5 back. The bellboy can't split the $5 evenly, so he gives $1 to each person and keeps $2 for himself. Each person paid $9, totaling $27. Adding the $2 kept by the bellboy makes $29. Where is the missing dollar? |
| 4 | The Light Switch Puzzle | You are in a room with three light switches that correspond to three light bulbs in another room. You can only go into the other room once. How do you determine which switch corresponds to which bulb? |
| 5 | The Coin Weighing Puzzle | You have 12 coins, and one of them is fake (heavier or lighter). You have a balance scale and can use it three times. How do you identify the fake coin? |
| 6 | The Chessboard Puzzle | You have a standard 8x8 chessboard with two diagonally opposite corners removed. Can you cover the remaining board with 31 dominoes (each covering two squares)? |
| 7 | The Frog and the Well | A frog is at the bottom of a 20-meter well. It can jump 3 meters up but slides back 2 meters after each jump. How many jumps does it take for the frog to reach the top? |
| 8 | The Monty Hall Problem | You're on a game show with three doors: behind one is a car, and behind the others are goats. You choose a door, and the host, who knows what's behind the doors, opens another door revealing a goat. You are then given a chance to switch your choice. Should you switch, and why? |
| 9 | The Birthday Paradox | In a room of 23 people, what is the probability that at least two people share the same birthday? |
| 10 | The Crossing Bridge Puzzle | Four people need to cross a bridge at night with one flashlight. They can only cross two at a time, and they take 1, 2, 5, and 10 minutes respectively to cross. When two people cross, they must go at the slower person's pace. How do they all get across in 17 minutes? |
| 11 | The Three Switches Puzzle | You are in a room with three switches. One of the switches controls a light bulb in another room. You can only check the bulb once. How can you determine which switch controls the bulb? |
| 12 | The Camel and Bananas Puzzle | A camel must transport 3000 bananas across a 1000-mile desert. The camel can carry a maximum of 1000 bananas at a time and eats one banana every mile it walks. What is the maximum number of bananas the camel can transport across the desert? |
| 13 | The Handshake Puzzle | At a party, everyone shook hands with everybody else. There were 66 handshakes. How many people were at the party? |
| 14 | The Hourglass Puzzle | You have a 4-minute hourglass and a 7-minute hourglass. How can you measure exactly 9 minutes? |
| 15 | The Apple Basket Puzzle | You have 10 baskets, each with 10 apples. Each apple weighs 1 kg, except one basket where each apple weighs 0.9 kg. How do you find the basket with the lighter apples using a digital scale only once? |
| 16 | The Egg Drop Puzzle | You have two identical eggs and access to a 100-story building. The eggs break if dropped from a certain floor and above. How do you find the highest floor from which you can drop an egg without breaking it, using the fewest drops? |
| 17 | The Wolf, Goat, and Cabbage Puzzle | A farmer needs to get a wolf, a goat, and a cabbage across a river. He has a boat that can carry only him and one other item at a time. How does he do it without leaving the wolf alone with the goat or the goat alone with the cabbage? |
| 18 | The Rope Burning Puzzle | You have two ropes and a lighter. Each rope takes exactly one hour to burn, but they do not burn at a constant rate. How do you measure exactly 45 minutes? |
| 19 | The Manhole Cover Puzzle | Why are manhole covers round? |
| 20 | The Chicken and Egg Problem | Which came first, the chicken or the egg? |
| 21 | The Fish Weighing Puzzle | You have a fish that weighs 12 grams plus half of its own weight. How much does the fish weigh? |
| 22 | The Two Sons Riddle | A man is looking at a picture of someone. His friend asks, "Who is it you are looking at?" The man replies, "Brothers and sisters I have none, but that man's father is my father's son." Who is in the picture? |
| 23 | The Frog and Stones Puzzle | There are 10 stones in a row. A frog can jump over one or two stones. How many different ways can the frog reach the 10th stone? |
| 24 | The Light Bulbs in a Row Puzzle | You have 100 light bulbs in a row, all initially turned off. You toggle every second bulb, then every third bulb, and so on until you toggle the 100th bulb. How many bulbs are left on? |
| 25 | The Farmer and the Three Sons Puzzle | A farmer wants to divide his 17 horses among his three sons. He wants to give half to the first son, one-third to the second son, and one-ninth to the third son. How does he do it without cutting any horses? |
Why Puzzles Are Asked in Interviews?
Interview puzzles aren’t random. They assess your structured thinking and clarity of logic rather than memorized formulas. Companies use them to evaluate how candidates handle ambiguity and design strategies from limited data.
By solving puzzles, you show your ability to break problems into steps, validate assumptions, and justify solutions, crucial in programming, analytics, and management roles.
Tips to Solve Interview Puzzles Effectively
- Think aloud – Interviewers care about your reasoning, not just the answer.
- Break it down – Simplify problems into smaller steps or states.
- Use logic patterns – Many puzzles follow parity, combination, or probability logic.
- Avoid guessing – Build your argument based on given constraints.
- Practice daily – Solve 1–2 puzzles a day from reliable reasoning sources.
FAQs about Puzzles
Q1. What are the most asked puzzles in interviews?
The most common ones include the Egg Dropping Puzzle, Monty Hall Problem, Bridge Crossing Puzzle, and 100 Bulbs Problem. These puzzles test reasoning depth and pattern recognition.
Q2. Are puzzles really used in coding or tech interviews?
Yes. Companies like Google, Amazon, Facebook, and Microsoft often use logic puzzles to check problem-solving under time pressure.
Q3. Are puzzles part of government or aptitude exams?
Definitely. Exams like CAT, UPSC, SSC, and IBPS regularly include logic puzzles to evaluate analytical aptitude.
Q4. Where can I practice puzzles with visuals and answers?
You can find interactive puzzle guides with diagrams, animations, and solutions on Scholar247.org, where puzzles are regularly updated and visualized for clarity.