# Visual puzzles with detailed solutions | SwaVid Try SwaVid's visual maths and logic puzzles, then learn from a clear step-by-step solution. Canonical: https://www.swavid.com/puzzles Source: https://www.swavid.com/puzzles # Look closely. Think slowly. ## The snail and the 10-metre well ## The doubling lily pond ## The cupcake machines ## Up 25%, then down 25% ## Find the lighter coin ## Draw two aces in a row ## Count the edge cubes ## 100 machines, 100 items ## How many squares are there? ## Only 3 cuts allowed ## Move one matchstick: 6 + 4 = 4 ## How long for 12 strikes? ## Count the handshakes ## How many digits are written? ## Measure exactly 4 litres ## Divide 30 by half, then add 10 ## The bat and ball ## The snail in the well ## How many of each animal? ## Find the two integers ## When does the train clear the platform? ## How many zeroes end 100!? ## Every label is wrong ## How often do the hands meet? ## Which melts first? ## What changes first? ## Which bubble grows? ## Above or below? ## What is the number? ## The Missing Number Pyramid ## Three friends check into a hotel ## A shopkeeper sells two shirts SwaVid puzzle library Visual maths and logic challenges, each followed by the complete reasoning rather than only an answer. A snail is at the bottom of a 10-metre well. Every day it climbs 3 metres, and every night it slips down 2 metres. On which day does it get out? A patch of lily pads doubles in area every day. It completely covers the pond today. When was the pond exactly half covered? Five identical machines make five cupcakes in five minutes. Working at the same rate, how long will 100 machines take to make 100 cupcakes? A quantity increases by 25% and then decreases by 25%. Does it return to its starting value? If not, what is the overall percentage change? Nine identical coins include one lighter coin. Can you identify it with exactly two balance-scale weighings? From a standard 52-card deck, what is the probability of drawing two aces without replacement? A cube is painted on every face, then cut into 27 equal cubes. How many small cubes have exactly two painted faces? 5 machines make 5 items in 5 minutes. How long do 100 machines take to make 100 items? A standard 8×8 chessboard contains how many squares in total, not just the 64 smallest ones? What is the maximum number of pieces you can make from one pizza with 3 straight cuts? Move exactly one matchstick to make the equation 6 + 4 = 4 true. A clock takes 5 seconds to strike 6 times. At the same rhythm, how long does it take to strike 12 times? Ten people each shake hands with every other person once. How many handshakes happen? Write every whole number from 1 through 100 with no spaces. How many digits do you write in total? You have an empty 3 L jug and an empty 5 L jug. How can you measure exactly 4 L of water? Divide 30 by half, then add 10. What do you get? A bat and ball cost ₹110. The bat costs ₹100 more than the ball. What does the ball cost? A snail climbs 3 m each day and slips 2 m each night. How long does it take to escape a 10 m well? A farm has 35 chickens and rabbits in total. Together they have 94 legs. How many chickens and rabbits are there? Two positive consecutive integers multiply to 156. What are the integers? A 180 m train travels at 54 km/h. How many seconds does it take to completely pass a 270 m platform? The number 100! equals 100 × 99 × 98 × … × 1. How many consecutive zeroes are at its end? Three boxes say APPLES, ORANGES, and MIXED. Every label is wrong. One fruit draw must fix all labels. Which box? During one complete 12-hour cycle, how many times do a clock's hour and minute hands overlap? Two identical ice cubes start at 0°C. Salt is sprinkled on one. Which cube begins melting faster? (Room temperature is the same for both.) A spinning skater pulls both arms inward. Does the rotation speed increase, decrease, or stay constant? (External torque is negligible.) Two soap bubbles of different sizes are connected by a tube. When the valve opens, which bubble grows? (Both bubbles use the same soap film.) Inside a sealed pressure cooker, does water boil above or below 100°C? (Outside pressure is normal sea-level pressure.) A two-digit number has digits summing to 9. Reversing its digits makes it 27 smaller. Find the number. Look at the number pyramid in the image. Which number replaces the question mark? Hint: It is not as random as it looks. There is a pattern in the way the numbers are built. Three friends check into a hotel. The room is ₹300, so they pay ₹100 each. Later the manager realises the room is only ₹250 and sends the bellboy back with ₹50. The bellboy keeps ₹20 and returns ₹10 to each friend. So each friend paid ₹90. That's ₹270. Plus the bellboy's ₹20 = ₹290. Where did the missing ₹10 go? A shopkeeper sells two shirts for ₹600 each. On one he makes a 20% profit. On the other he takes a 20% loss. Overall: profit, loss, or break even? ## Key Links - [Puzzle 1 The snail and the 10-metre well A snail is at the bottom of a 10-metre well. Every day it climbs 3 metres, and every night it slips down 2 metres. On which day does it get out? See puzzle and solution](https://www.swavid.com/puzzles/quiz-1) - [Puzzle 2 The doubling lily pond A patch of lily pads doubles in area every day. It completely covers the pond today. When was the pond exactly half covered? See puzzle and solution](https://www.swavid.com/puzzles/quiz-2) - [Puzzle 3 The cupcake machines Five identical machines make five cupcakes in five minutes. Working at the same rate, how long will 100 machines take to make 100 cupcakes? See puzzle and solution](https://www.swavid.com/puzzles/quiz-3) - [Puzzle 4 Up 25%, then down 25% A quantity increases by 25% and then decreases by 25%. Does it return to its starting value? If not, what is the overall percentage change? See puzzle and solution](https://www.swavid.com/puzzles/quiz-4) - [Puzzle 5 Find the lighter coin Nine identical coins include one lighter coin. Can you identify it with exactly two balance-scale weighings? See puzzle and solution](https://www.swavid.com/puzzles/nine-coins) - [Puzzle 6 Draw two aces in a row From a standard 52-card deck, what is the probability of drawing two aces without replacement? See puzzle and solution](https://www.swavid.com/puzzles/two-aces) - [Puzzle 7 Count the edge cubes A cube is painted on every face, then cut into 27 equal cubes. How many small cubes have exactly two painted faces? See puzzle and solution](https://www.swavid.com/puzzles/painted-cube) - [Puzzle 8 100 machines, 100 items 5 machines make 5 items in 5 minutes. How long do 100 machines take to make 100 items? See puzzle and solution](https://www.swavid.com/puzzles/machines-and-items) - [Puzzle 9 How many squares are there? A standard 8×8 chessboard contains how many squares in total, not just the 64 smallest ones? See puzzle and solution](https://www.swavid.com/puzzles/chessboard-squares) - [Puzzle 10 Only 3 cuts allowed What is the maximum number of pieces you can make from one pizza with 3 straight cuts? See puzzle and solution](https://www.swavid.com/puzzles/pizza-cuts) - [Puzzle 11 Move one matchstick: 6 + 4 = 4 Move exactly one matchstick to make the equation 6 + 4 = 4 true. See puzzle and solution](https://www.swavid.com/puzzles/matchstick-equation) - [Puzzle 12 How long for 12 strikes? A clock takes 5 seconds to strike 6 times. At the same rhythm, how long does it take to strike 12 times? See puzzle and solution](https://www.swavid.com/puzzles/clock-strikes) - [Puzzle 13 Count the handshakes Ten people each shake hands with every other person once. How many handshakes happen? See puzzle and solution](https://www.swavid.com/puzzles/handshakes) - [Puzzle 14 How many digits are written? Write every whole number from 1 through 100 with no spaces. How many digits do you write in total? See puzzle and solution](https://www.swavid.com/puzzles/counting-digits) - [Puzzle 15 Measure exactly 4 litres You have an empty 3 L jug and an empty 5 L jug. How can you measure exactly 4 L of water? See puzzle and solution](https://www.swavid.com/puzzles/water-jugs) - [Puzzle 16 Divide 30 by half, then add 10 Divide 30 by half, then add 10. What do you get? See puzzle and solution](https://www.swavid.com/puzzles/divide-by-half) - [Puzzle 17 The bat and ball A bat and ball cost ₹110. The bat costs ₹100 more than the ball. What does the ball cost? See puzzle and solution](https://www.swavid.com/puzzles/bat-and-ball) - [Puzzle 18 The snail in the well A snail climbs 3 m each day and slips 2 m each night. How long does it take to escape a 10 m well? See puzzle and solution](https://www.swavid.com/puzzles/snail-in-well) - [Puzzle 19 How many of each animal? A farm has 35 chickens and rabbits in total. Together they have 94 legs. How many chickens and rabbits are there? See puzzle and solution](https://www.swavid.com/puzzles/chickens-rabbits) - [Puzzle 20 Find the two integers Two positive consecutive integers multiply to 156. What are the integers? See puzzle and solution](https://www.swavid.com/puzzles/consecutive-product) - [Puzzle 21 When does the train clear the platform? A 180 m train travels at 54 km/h. How many seconds does it take to completely pass a 270 m platform? See puzzle and solution](https://www.swavid.com/puzzles/train-platform) - [Puzzle 22 How many zeroes end 100!? The number 100! equals 100 × 99 × 98 × … × 1. How many consecutive zeroes are at its end? See puzzle and solution](https://www.swavid.com/puzzles/trailing-zeroes) - [Puzzle 23 Every label is wrong Three boxes say APPLES, ORANGES, and MIXED. Every label is wrong. One fruit draw must fix all labels. Which box? See puzzle and solution](https://www.swavid.com/puzzles/mislabeled-boxes) - [Puzzle 24 How often do the hands meet? During one complete 12-hour cycle, how many times do a clock's hour and minute hands overlap? See puzzle and solution](https://www.swavid.com/puzzles/clock-overlaps) - [New puzzle Which melts first? Two identical ice cubes start at 0°C. Salt is sprinkled on one. Which cube begins melting faster? (Room temperature is the same for both.) See puzzle and solution](https://www.swavid.com/puzzles/salted-ice) - [New puzzle What changes first? A spinning skater pulls both arms inward. Does the rotation speed increase, decrease, or stay constant? (External torque is negligible.) See puzzle and solution](https://www.swavid.com/puzzles/spinning-skater) - [New puzzle Which bubble grows? Two soap bubbles of different sizes are connected by a tube. When the valve opens, which bubble grows? (Both bubbles use the same soap film.) See puzzle and solution](https://www.swavid.com/puzzles/two-soap-bubbles-which-grows) - [New puzzle Above or below? Inside a sealed pressure cooker, does water boil above or below 100°C? (Outside pressure is normal sea-level pressure.) See puzzle and solution](https://www.swavid.com/puzzles/pressure-cooker-boiling-point) - [New puzzle What is the number? A two-digit number has digits summing to 9. Reversing its digits makes it 27 smaller. Find the number. See puzzle and solution](https://www.swavid.com/puzzles/reversed-digits-sum-nine) - [New puzzle The Missing Number Pyramid Look at the number pyramid in the image. Which number replaces the question mark? Hint: It is not as random as it looks. There is a pattern in the way the numbers are built. See puzzle and solution](https://www.swavid.com/puzzles/missing-number-pyramid) - [New puzzle Three friends check into a hotel Three friends check into a hotel. The room is ₹300, so they pay ₹100 each. Later the manager realises the room is only ₹250 and sends the bellboy back with ₹50. The bellboy keeps ₹20 and returns ₹10 to each friend. So each friend paid ₹90. That's ₹270. Plus the bellboy's ₹20 = ₹290. Where did the missing ₹10 go? See puzzle and solution](https://www.swavid.com/puzzles/three-friends-hotel) - [New puzzle A shopkeeper sells two shirts A shopkeeper sells two shirts for ₹600 each. On one he makes a 20% profit. On the other he takes a 20% loss. Overall: profit, loss, or break even? See puzzle and solution](https://www.swavid.com/puzzles/shopkeeper-two-shirts)