Logic puzzles with answers
These logic puzzles train the part of your brain that spots rules, tests ideas and throws out answers that cannot work. On this page you will find 50 logical questions with answers, from gentle warm ups to number patterns, knights and knaves, seating puzzles and a few truly hard ones.
Every answer comes with a short line of working, so you can check your thinking instead of just reading the result. Try each puzzle with a pencil first, then tap to see the answer and the reason.
Easy logic questions with answers
Riddle 1
Tara is older than Ben, and Ben is older than Mia. Who is the youngest of the three?
Show answer
MiaThe order is Tara, then Ben, then Mia, so Mia comes last in age.
Riddle 2
Every zib is a tock, and every tock is a mup. Is every zib a mup?
Show answer
YesZibs sit inside the tock group, and the whole tock group sits inside the mup group, so every zib is a mup.
Riddle 3
Five books stand on a shelf. The blue book is on the far left and the red book is exactly in the middle. How many books are between them?
Show answer
OneWith five books the middle is spot 3 and blue is spot 1, so only the book in spot 2 sits between them.
Riddle 4
Some cats in a pet shop are black. Everything black in the shop is for sale. Must every cat in the shop be for sale?
Show answer
No, only the black catsThe rule only covers black things, so a white or ginger cat may not be for sale.
Riddle 5
Mira's house is east of the school. The park is east of her house. Which way is the school from the park?
Show answer
WestThe order from west to east is school, house, park, so from the park the school lies to the west.
Riddle 6
Gopal, Hema and Ishan each own one pet: a cat, a dog or a fish. Gopal's pet has no fur, and Hema's pet barks. Who owns the cat?
Show answer
IshanGopal's furless pet must be the fish and Hema's barking pet is the dog, so the cat belongs to Ishan.
Riddle 7
If the day after tomorrow is Friday, what day was yesterday?
Show answer
TuesdayTwo days before Friday is Wednesday, which is today, so yesterday was Tuesday.
Riddle 8
In a running race you overtake the person in second place. What place are you in now?
Show answer
SecondYou take the place of the runner you passed, which is second, and the leader is still ahead.
Number pattern logic questions
Riddle 9
What comes next: 2, 6, 12, 20, 30, ?
Show answer
42Each term is n times (n + 1): 1x2, 2x3, 3x4, 4x5, 5x6, so next is 6x7 = 42.
Riddle 10
Find the next number: 1, 1, 2, 3, 5, 8, ?
Show answer
13Each number is the sum of the two before it, so 5 + 8 = 13.
Riddle 11
Continue the pattern: 3, 6, 11, 18, 27, ?
Show answer
38The gaps are 3, 5, 7, 9, so the next gap is 11 and 27 + 11 = 38. These are the square numbers plus 2.
Riddle 12
Fill the gap: 4, 9, 16, ?, 36
Show answer
25These are square numbers 2x2, 3x3, 4x4, so the gap is 5x5 = 25.
Riddle 13
Look at 81, 27, 9, 3. Which number follows?
Show answer
1Each number is divided by 3, so 3 / 3 = 1.
Riddle 14
The list 2, 3, 5, 7, 11, 13 follows one rule. What number fits after 13?
Show answer
17These are prime numbers in order, and the next prime after 13 is 17.
Riddle 15
Which number does not belong: 8, 27, 64, 100, 125?
Show answer
1008, 27, 64 and 125 are cubes (2, 3, 4 and 5 cubed), but 100 is a square, not a cube.
Riddle 16
Spot the rule and give the next number: 1, 4, 13, 40, ?
Show answer
121Each number is three times the last plus 1, so 40 x 3 + 1 = 121.
Truth teller and liar puzzles
Riddle 17
On an island, knights always tell the truth and knaves always lie. A visitor hears someone say, "I am a knave." Is the speaker an islander?
Show answer
No, no islander can say thatA knight would be lying and a knave would be telling the truth, so neither type could say it.
Riddle 18
Kabir says, "Dev is a knave." Dev says, "Kabir and I are the same type." Knights always tell the truth and knaves always lie. What are they?
Show answer
Kabir is a knight, Dev a knaveChecking all four cases, only Kabir knight and Dev knave works: Kabir's claim is true and Dev's claim is false.
Riddle 19
Exactly one of three friends always lies. Arun says, "Bela is the liar." Bela says, "I am not the liar." Chetan says, "Arun is not the liar." Who is lying?
Show answer
BelaIf Bela lies, Arun and Chetan both speak truly, which fits. Making Arun or Chetan the liar creates a second false statement.
Riddle 20
Asha says, "Bilal is lying." Bilal says, "Chitra is lying." Chitra says, "Asha and Bilal are both lying." Who is telling the truth?
Show answer
Only BilalTesting all eight true or false patterns, only Bilal true with Asha and Chitra false keeps every statement consistent.
Riddle 21
Two guards stand at a gate. One always lies and one always tells the truth. You ask one guard, "Are you the liar?" and he says no. What have you learned?
Show answer
Nothing at allThe truthful guard would say no, and the liar would also say no, so the answer cannot tell them apart.
Riddle 22
One of four cousins ate the last laddoo. Om says, "Pia ate it." Pia says, "Raj ate it." Raj says, "Pia is lying." Sam says, "I did not eat it." Only one cousin tells the truth. Who ate it?
Show answer
SamIf Sam ate it, only Raj's statement is true. Every other choice makes two or more statements true.
Riddle 23
Neel says, "At least one of the two of us is a knave." Ira says nothing. Knights tell the truth and knaves lie. What are Neel and Ira?
Show answer
Neel is a knight, Ira a knaveA knave Neel would be speaking the truth, which is impossible, so Neel is a knight and his claim makes Ira a knave.
Riddle 24
One of three boxes holds a prize. Box A says, "The prize is here." Box B says, "The prize is not here." Box C says, "The prize is not in A." Only one label is true. Where is the prize?
Show answer
Box BWith the prize in B, only label C is true. In A, labels A and B are both true, and in C, labels B and C are both true.
Seating, order and arrangement puzzles
Riddle 25
Five children stand in a line. Di is last. Cy stands right behind Ali. Ali is ahead of Bo. Bo is not next to Di. Eva is not first. Who is in the middle?
Show answer
BoThe only order that fits every rule is Ali, Cy, Bo, Eva, Di, so Bo stands third.
Riddle 26
Mona is 3 years older than Nina. In 5 years their ages will add up to 33. How old is Nina now?
Show answer
10In 5 years the ages are (n + 5) and (n + 8), so 2n + 13 = 33 and n = 10.
Riddle 27
Four houses in a row are red, blue, green and yellow. Yellow is on the far left. Red is not at either end. Green is just left of blue. What is the order from left to right?
Show answer
Yellow, red, green, blueYellow takes spot 1, and green and blue must be a side by side pair, which only leaves red in spot 2 and the pair in spots 3 and 4.
Riddle 28
Four friends sit around a square table, one on each side. Pia faces Quin. Ravi sits on Pia's left. Who sits on Pia's right?
Show answer
SonaQuin is opposite Pia and Ravi takes her left side, so the only seat left for Sona is on Pia's right.
Riddle 29
Six children sit in a row. Qadir is at the left end with Neha next to him. Lalit is at the right end with Pinky beside him. Mohan sits between Neha and Om. Who is third from the left?
Show answer
MohanQadir, Neha fill seats 1 and 2, and Pinky, Lalit fill 5 and 6. Mohan must be next to Neha in seat 3, leaving seat 4 for Om.
Riddle 30
Ira is taller than Jay but shorter than Kim. Lea is shorter than Jay. Moe is taller than Kim. Who is in the middle by height?
Show answer
IraFrom tallest the order is Moe, Kim, Ira, Jay, Lea, so Ira is third of five.
Riddle 31
Three jars are labelled Sugar, Salt and Mixed, and every label is wrong. You may taste one spoonful from one jar. Which jar should you taste?
Show answer
The jar labelled MixedThat jar must be pure sugar or pure salt, so one taste names it. The other two jars then have only one possible way to be relabelled.
Riddle 32
In a certain year, 1 March falls on a Monday. What day of the week is 1 April?
Show answer
ThursdayMarch has 31 days, and 31 leaves a remainder of 3 when divided by 7, so the day moves 3 places from Monday to Thursday.
Riddle 33
Maths, Art, Hindi and Music are taught on Monday to Thursday, one a day. Music is on Monday. Art comes after Hindi. Maths is not on Thursday and not the day after Music. Which day is Maths?
Show answer
WednesdayMaths cannot be Tuesday or Thursday, so it is Wednesday, leaving Hindi on Tuesday and Art on Thursday.
Weighing, counting and measuring puzzles
Riddle 34
You have 9 coins that look alike, but one is a little heavier. What is the fewest number of balance weighings that always finds it?
Show answer
2Weigh 3 against 3 to find the group of three with the heavy coin, then weigh 1 against 1 from that group.
Riddle 35
You have a 3 litre jug and a 5 litre jug, and a tap. How can you measure exactly 4 litres?
Show answer
Leave 4 litres in the 5 litre jugFill the 5, pour into the 3 (2 left), empty the 3, pour the 2 in, fill the 5 again, then top up the 3, leaving 4.
Riddle 36
A rope takes exactly one hour to burn from end to end, but it burns unevenly. How can you time 30 minutes?
Show answer
Light both ends at onceTwo flames burning toward each other always meet after half the total time, however uneven the rope.
Riddle 37
A straight fence is 88 metres long, with a post every 4 metres including both ends. How many posts are there?
Show answer
23 posts88 / 4 gives 22 gaps, and a row with 22 gaps needs one more post than gaps, so 23.
Riddle 38
A dark drawer holds 4 red, 6 blue and 8 green socks. How many must you pull out to be sure of two socks of the same colour?
Show answer
4With three colours you could pull 3 different socks, so the 4th sock must match one of them.
Riddle 39
Eight players each shake hands once with every other player. How many handshakes happen?
Show answer
28Each of 8 people shakes 7 hands, giving 56, but every handshake is counted twice, so 56 / 2 = 28.
Riddle 40
The pages of a book are numbered from 1 to 120. How many times is the digit 1 printed?
Show answer
53Counting the 1s in every page number from 1 to 120 gives 12 in the units place, 20 in the tens place and 21 in the hundreds place.
Riddle 41
Ten machines make ten toys in ten minutes. How long do fifty machines take to make fifty toys?
Show answer
10 minutesEach machine makes one toy in ten minutes, so fifty machines working together also need ten minutes.
Hard logic puzzles for adults and teens
Riddle 42
Statement 1: exactly one of these is false. Statement 2: exactly two are false. Statement 3: all three are false. Which statement is true?
Show answer
Statement 2If only statement 2 is true, then two statements are false, which is exactly what it says. No other pattern is consistent.
Riddle 43
A father is four times as old as his son. In 20 years he will be twice as old as his son. How old is the son now?
Show answer
104s + 20 = 2(s + 20) gives 2s = 20, so the son is 10 and the father is 40.
Riddle 44
I am a two digit number. My digits add up to 11, and if you swap them I become 27 bigger. What number am I?
Show answer
47Swapping raises the number by 9 times the gap between digits, so the gap is 3, and digits 4 and 7 add to 11.
Riddle 45
Twenty closed lockers stand in a row. Student 1 opens all of them, student 2 flips every 2nd one, student 3 every 3rd, and so on up to student 20. How many end open?
Show answer
4Only lockers with an odd number of factors stay open, which are the squares 1, 4, 9 and 16.
Riddle 46
A train leaves at 60 km/h. One hour later a second train leaves the same station on the same track at 80 km/h. How long after leaving does the second train catch up?
Show answer
3 hoursThe first train is 60 km ahead and the gap closes at 20 km/h, so 60 / 20 = 3 hours.
Riddle 47
There are 30 students in a class. What is the largest number you can promise were born in the same month?
Show answer
3Spread 30 birthdays across 12 months as evenly as possible and some month still gets 3, since 12 x 2 = 24 is less than 30.
Riddle 48
How many two digit numbers have digits that add up to 9?
Show answer
9They are 18, 27, 36, 45, 54, 63, 72, 81 and 90, which makes nine numbers.
Riddle 49
A says, "B and C are both knaves." B says, "A is a knave." C says, "B is a knave." Knights tell the truth and knaves lie. Who is the knight?
Show answer
Only BChecking all eight cases, only A knave, B knight and C knave makes every statement match its speaker.
Riddle 50
Six teams play in a league and every team plays every other team once. How many matches are played in total?
Show answer
15Each team plays 5 matches, giving 6 x 5 = 30, but each match involves two teams, so 30 / 2 = 15.
Logic puzzles: images to share
Save any card and share it. The answer is printed upside down at the bottom of each card.
How to use these riddles
Use these logic questions as a warm up at the start of a maths or reasoning class, a quiz round at home, or a quiet challenge on a long train ride. For younger children, start with the easy section and read the question aloud twice. Teens and adults can jump straight to the liar puzzles and the hard section.
When a puzzle feels stuck, write down every possible case and cross out the ones that break a rule. Draw a small line or table for seating and order puzzles. For truth and lie puzzles, pretend one person is honest and see whether the story holds together. If it falls apart, switch and try again. Most logic puzzles crack open once you test each case calmly.
Tips
- List every possible case on paper and cross out the ones that break a clue.
- For seating and order puzzles, draw boxes in a row or around a table before you place anyone.
- Read the question twice, because one small word like "only" or "not" often decides the answer.
More riddles and puzzles
Questions people ask
What are logic puzzles?
Logic puzzles are questions you solve by careful reasoning rather than general knowledge. Each one gives a few clues, and only one answer fits all of them.
Are logical questions good for kids?
Yes. Easy logical questions teach children to read carefully, follow rules and check their answers. Start with the easy and number pattern sections and move up slowly.
How do I solve logic questions faster?
Write the clues down, test each possible case and cross out the ones that fail. With practice you will spot common tricks, such as a statement that no one could ever say truthfully.
What is a knights and knaves puzzle?
It is a puzzle where knights always tell the truth and knaves always lie. You decide who is who by testing whether each person's words match their type.
Where can I use logical questions with answers?
They work well in class warm ups, aptitude test practice, family quiz nights and interviews. The short working under each answer makes them easy to explain to others.
Every riddle on this page is written and checked by the Paheli World team. How we make our riddles.