Are you searching for the best Google interview riddles to test your brain or prepare for a big tech interview? Look no further! As soon as you opened this article, your hunt for the perfect riddles is over.
We’ve gathered the most exciting, trending, and clever riddles that Google loves to challenge candidates with.
These brain teasers are simple enough for an 8-year-old to understand and share with their family.
With 8 categories and riddles each, you’ll have plenty of fun puzzles to solve. Let’s dive into the world of Google interview riddles! 😊
Logic Puzzles 🧠
Logic puzzles make you think step-by-step to find the answer. Google loves these to test how you solve problems. Here are 10 fun ones!
- You have 8 bags of gold coins, each with 100 coins. Seven bags have real coins weighing 10 grams each, but one bag has fake coins weighing 9 grams. You can use a scale only once. How do you find the fake bag?
Answer: Take 1 coin from bag 1, 2 from bag 2, and so on, up to 8 from bag 8. Weigh them. If all were real, the weight would be 450 grams. The actual weight will be less, and the difference tells you the fake bag’s number. - Three houses in a row are numbered 1, 2, 3 from left to right. Each has a different color: red, blue, green. The green house is left of the red house. The blue house is number 2. What color is house 3?
Answer: Red. - You have two ropes. Each burns in exactly 1 hour, but not evenly. How do you measure 45 minutes using only these ropes and a lighter?
Answer: Light both ends of one rope and one end of the other. When the first rope is gone (30 minutes), light the other end of the second rope. It will burn out in 15 more minutes, totaling 45 minutes. - A cake has 3 candles. You can light them, but the wind blows one out every second. How many are lit after 3 seconds?
Answer: 2. Relight a candle each second; one gets blown out, leaving 2 lit. - You’re in a room with 3 light switches, each controlling a different bulb in another room. You can’t see the bulbs. You can flip switches, then check the bulbs once. How do you know which switch controls which bulb?
Answer: Turn on switch 1 for 5 minutes, then turn it off. Turn on switch 2. Check the bulbs: the hot but off bulb is switch 1, the on bulb is switch 2, the cold off bulb is switch 3. - A man has 3 hats: red, blue, green. He picks one randomly each day. What’s the chance he wears the red hat two days in a row?
Answer: 1/9. Each day, he has a 1/3 chance of picking red, so two days is 1/3 × 1/3 = 1/9. - You have 4 pills: 2 safe, 2 poison. You must take exactly 2 pills, one from each of two bottles. One bottle has 2 safe pills, the other has 2 poison. How do you ensure you take safe pills?
Answer: Take one pill from each bottle. - A river has a boat that can carry you and one item. On one side are a fox, a chicken, and grain. You need them all on the other side without the fox eating the chicken or the chicken eating the grain. How?
Answer: Take the chicken across. Go back, take the fox across, bring the chicken back. Take the grain across, go back, take the chicken across. - You have 9 coins, one heavier than the others. Using a balance scale twice, how do you find the heavier coin?
Answer: Divide into 3 groups of 3. Weigh two groups. If they balance, the heavy coin is in the third group. If not, it’s in the heavier group. Weigh 2 coins from that group. If they balance, the third coin is heavy; otherwise, the heavier coin is the answer. - A clock shows 3:00. After 65 minutes, what’s the angle between the hour and minute hands?
Answer: 30 degrees. The minute hand moves 6 degrees per minute (65 × 6 = 390, or 30 after a full circle). The hour hand moves 0.5 degrees per minute (65 × 0.5 = 32.5). The angle is |30 – 32.5| = 2.5, but relative position gives 30 degrees.
Math Brain Teasers 🔢
Math riddles test your number skills. These are simple but tricky!
- If you have 10 apples and give half to your friend, how many do you have left?
Answer: 5. - A snail climbs a 10-meter pole. It climbs 3 meters each day and slips 2 meters at night. How many days to reach the top?
Answer: 8. It reaches 10 meters on day 8 before slipping. - You have 5 cookies and want to share them equally among 3 friends. How many does each get?
Answer: 1, with 2 left over. - If a pizza is cut into 8 equal slices and you eat 3, what fraction is left?
Answer: 5/8. - A car travels 60 miles in 1 hour. How long to travel 30 miles?
Answer: 30 minutes. - You have 6 socks: 3 red, 3 blue. How many socks to pick to ensure a matching pair?
Answer: 3. Worst case, you pick 2 different colors, but the third matches one. - If 2 cats catch 2 mice in 2 minutes, how long for 4 cats to catch 4 mice?
Answer: 2 minutes. Each cat catches one mouse in 2 minutes. - A rectangle’s length is twice its width. If the perimeter is 24, what’s the area?
Answer: 32. Width = 4, length = 8, so area = 4 × 8 = 32. - You roll two dice. What’s the chance the sum is 7?
Answer: 1/6. There are 6 ways to get 7 (1+6, 2+5, 3+4, 4+3, 5+2, 6+1) out of 36 possibilities. - If eggs cost 12 cents per dozen, how much for 3 eggs?
Answer: 3 cents. One egg is 1 cent, so 3 eggs = 3 cents.
Wordplay Riddles 📜
Word riddles twist language to make you think. Google loves these for creativity!
- What has keys but can’t open locks?
Answer: A piano. - I speak without a mouth and hear without ears. What am I?
Answer: An echo. - What comes once in a minute, twice in a moment, but never in a thousand years?
Answer: The letter M. - What has a neck but no head, a body but no legs, and arms but no hands?
Answer: A shirt. - I’m tall when I’m young, and short when I’m old. What am I?
Answer: A candle. - What starts with E, ends with E, and has one letter in the middle?
Answer: An envelope. - What word is spelled wrong in every dictionary?
Answer: None. Dictionaries spell words correctly. - I’m light as a feather, but you can’t hold me for long. What am I?
Answer: Breath. - What has one eye but can’t see?
Answer: A needle. - What gets wetter the more it dries?
Answer: A towel.
Lateral Thinking Puzzles 🤔
These riddles need you to think outside the box!
- A man walks into a bar and asks for water. The bartender pulls out a gun. Why?
Answer: The man has hiccups, and the bartender scares them away. - How can you make the number 8888 equal 1000?
Answer: Use Roman numerals: VIII = 8, so 8 + 8 + 8 + 8 = 32, but creatively, 8888 can be seen as 1000 by tilting the 8s to look like infinity symbols. - A woman has 7 daughters, and each daughter has a brother. How many children does she have?
Answer: 8. Seven daughters plus one son. - You’re in a dark room with a candle, a wood stove, and a gas lamp. You have one match. What do you light first?
Answer: The match. You must light it before anything else. - A man pushes his car to a hotel and tells the owner he’s bankrupt. Why?
Answer: He’s playing Monopoly. - How do you get 10 horses into 9 stables?
Answer: Put one horse in each of the first 8 stables, and put the last 2 horses in the 9th stable. - A plane crashes on the border of two countries. Where do they bury the survivors?
Answer: You don’t bury survivors. - If you aren’t impressed with the picture of the first Black president, why not?
Answer: It’s just a photo, not the person. - How can a man go 8 days without sleep?
Answer: He sleeps at night. - What do you throw out when you want to use it, but take in when you don’t?
Answer: An anchor.
Probability Puzzles 🎲
Probability riddles test your understanding of chance!
- You flip a coin 3 times. What’s the chance of getting exactly 2 heads?
Answer: 3/8. Possible outcomes are HHT, HTH, THH out of 8 total. - A bag has 3 red and 2 blue marbles. You draw 2 without looking. What’s the chance both are red?
Answer: 3/10. First draw: 3/5 for red. Second: 2/4 for red. Multiply: 3/5 × 2/4 = 3/10. - You have 2 buckets: one with 1 gold coin, one with 2 gold coins. You pick a bucket and draw a coin randomly. It’s gold. What’s the chance you picked the bucket with 2 coins?
Answer: 2/3. - You roll a die. What’s the chance of getting an even number?
Answer: 1/2. Three even numbers (2, 4, 6) out of 6. - A family has 2 children. At least one is a boy. What’s the chance both are boys?
Answer: 1/3. Possible pairs: BB, BG, GB. Only BB has both boys. - You pick a card from a deck. What’s the chance it’s a heart?
Answer: 1/4. There are 13 hearts in 52 cards. - You have 3 doors: 1 hides a car, 2 hide goats. You pick door 1. The host opens door 2, showing a goat, and asks if you want to switch to door 3. Should you switch?
Answer: Yes, switching gives a 2/3 chance of winning. - A spinner has 4 equal sections: red, blue, green, yellow. What’s the chance of landing on red twice in a row?
Answer: 1/16. Each spin is 1/4, so 1/4 × 1/4 = 1/16. - You draw 2 cards from a deck without replacing the first. What’s the chance both are aces?
Answer: 1/221. First ace: 4/52. Second ace: 3/51. Multiply: 4/52 × 3/51 = 1/221. - You toss 2 coins. What’s the chance at least one is heads?
Answer: 3/4. Only TT has no heads, so 1 – 1/4 = 3/4.
Spatial Reasoning Riddles 🌍
These riddles test how you think about shapes and space!
- A cube is painted red, then cut into 27 smaller cubes. How many have 3 painted faces?
Answer: 8. The 8 corner cubes have 3 painted faces. - You have a 3×3 grid. Place numbers 1 to 9 so each row, column, and diagonal sums to the same number. What’s the number?
Answer: 15. It’s a magic square. - A square garden has a path 1 meter wide around it. The path’s area is 36 square meters. What’s the garden’s area?
Answer: 64 square meters. - You have 8 queens on a chessboard. Can you place them so none attack each other?
Answer: Yes, one solution is placing queens at (1,2), (2,4), (3,6), (4,8), (5,3), (6,1), (7,7), (8,5). - A room is 4 meters by 5 meters. A spider is 1 meter up on one wall, and a fly is 1 meter up on the opposite wall. What’s the shortest path for the spider to reach the fly?
Answer: 7 meters. Unfold the room into a net; the shortest path is a straight line. - You have 5 points in a plane. What’s the maximum number of lines connecting pairs of points?
Answer: 10. Each point connects to 4 others, but divide by 2 to avoid double-counting. - A pizza is 12 inches wide. You cut a slice with a 60-degree angle. What’s the area of the slice?
Answer: 6π square inches. The pizza’s area is 36π, so a 60/360 slice is 6π. - You fold a square paper in half, then in half again. How many layers of paper are there?
Answer: 4. Each fold doubles the layers: 1 → 2 → 4. - A ladder is 5 meters long, leaning against a wall. The base is 3 meters from the wall. How high is the top?
Answer: 4 meters. Use the Pythagorean theorem: 5² = 3² + h², so h = 4. - You have a 4×4 grid. Color each square red or blue. Can you make it so no 2×2 section is all one color?
Answer: Yes, use a checkerboard pattern.
Algorithmic Thinking Riddles 💻
These riddles test how you break down problems like a coder!
- You have 25 horses and a 5-lane track. Find the 3 fastest horses with the fewest races. How many races?
Answer: 7. Race 5 groups of 5, take the top horse from each, race them, then race the top 3 with others based on group rankings. - You have 12 balls, one is heavier or lighter. Find the odd ball and whether it’s heavy or light in 3 weighings.
Answer: Divide into 3 groups of 4. Weigh 4 vs 4, then use logic to narrow down based on results. - You need to cross a bridge in 17 minutes. You and 3 friends take 1, 2, 5, and 10 minutes to cross. Only 2 can cross at a time, and you need a flashlight, which must be brought back. How?
Answer: 1 and 2 cross (2 min), 1 returns (1 min), 5 and 10 cross (10 min), 2 returns (2 min), 1 and 2 cross (2 min). Total: 17 minutes. - You have 100 floors and 2 eggs. Find the highest floor an egg can be dropped without breaking, using the fewest drops.
Answer: Use drops at floors 14, 27, 39, etc., adjusting based on breaks. Takes up to 14 drops. - You have 5 jars with 100 marbles each. One jar has marbles weighing 9 grams, others 10 grams. Find the odd jar in one weighing.
Answer: Take 1 marble from jar 1, 2 from jar 2, etc. Weigh them. The weight minus 450 grams tells the odd jar’s number. - You have 7 numbers: 1, 2, 3, 4, 5, 6, 7. Pick 4 numbers so no 2 differ by 1.
Answer: Pick 1, 3, 5, 7. - You have a list of 100 numbers, each from 1 to 100, but one is missing. Find the missing number.
Answer: Sum the numbers, subtract from the expected sum (5050), and the difference is the missing number. - You have 3 boxes: one with 2 gold coins, one with 2 silver coins, one with 1 gold and 1 silver. Pick a box and draw a coin randomly. It’s gold. What’s the chance the other coin in that box is gold?
Answer: 2/3. - You need to sort 5 numbers using only comparisons. What’s the minimum number of comparisons?
Answer: 7. Use a sorting algorithm like merge sort for 5 elements. - You have a 100-meter rope with knots every meter. Cut it into 100 pieces with one cut. How?
Answer: Tie the rope into a loop, then cut through all 100 segments at once.
Creative Problem-Solving Riddles 🎨
These riddles need imagination to solve!
- You have a cake and want to cut it into exactly 8 equal pieces with 3 cuts. How?
Answer: Cut horizontally through the middle, vertically through the center, and vertically again at 90 degrees. - You’re in a room with 2 exits. One leads to freedom, one to death. Two guards: one always lies, one always tells the truth. You can ask one question to one guard. What question?
Answer: Ask either guard, If I asked the other guard which door leads to freedom, what would he say? Take the opposite door. - You have 4 gallons of water and need exactly 2 gallons using a 5-gallon jug and a 3-gallon jug. How?
Answer: Fill the 5-gallon jug, pour into the 3-gallon jug, empty the 3-gallon jug, pour the remaining 2 gallons from the 5-gallon jug into the 3-gallon jug. - You have 10 boxes, each with 10 balls. One box has balls weighing 1 gram, others 2 grams. Find the odd box with one weighing.
Answer: Take 1 ball from box 1, 2 from box 2, etc. Weigh them. The weight minus 20 grams tells the odd box’s number. - You’re on an island with 3 chests: one with gold, one with silver, one empty. Each has a sign, but only one is true. Gold’s sign says This chest has gold, silver’s says This chest has silver, empty’s says The gold is not here. Which has gold?
Answer: The empty chest. Only its sign (The gold is not here) is true. - You have a 7-minute hourglass and a 4-minute hourglass. How do you measure 9 minutes?
Answer: Start both hourglasses. When the 4-minute one finishes, flip it. When the 7-minute one finishes, flip it. When the 4-minute one finishes again, flip the 7-minute one. The time from start to this flip is 9 minutes. - You have 6 matches. Make 4 equilateral triangles.
Answer: Form a tetrahedron (3D triangle) with each face as an equilateral triangle. - You need to measure 1 cup of flour, but you only have a 3-cup and a 5-cup bowl. How?
Answer: Fill the 5-cup bowl, pour into the 3-cup bowl, leaving 2 cups in the 5-cup bowl. Empty the 3-cup bowl, pour the 2 cups into it, fill the 5-cup bowl, and pour from it into the 3-cup bowl until full. The 5-cup bowl now has 4 cups. Repeat, but stop when 1 cup remains in the 5-cup bowl. - You have 3 ants at the corners of a triangle. They start walking along the edges at the same speed toward the next ant. Do they meet?
Answer: Yes, they meet at the center after spiraling inward. - You have a rope that burns in 1 minute. How do you measure 30 seconds?
Answer: Light both ends of the rope. It takes 30 seconds to burn completely.
Conclusion
This article is your one-stop guide to the best Google interview riddles! With riddles across 8 exciting categories, you’ve got plenty of brain teasers to challenge yourself, impress friends, or prepare for a tech interview.
Each riddle is simple enough for kids to understand and fun for everyone to solve. Keep practicing, and you’ll be a riddle master in no time! 😄
