Logic puzzles can fall into the category ofmathematics, but they are true works of art. These word challenges will test your thinking skills and inspire you to think harder than ever. After you start solving thesePuzzle, but you'll begin to see common patterns and themes: how to cross rivers, cheat death, and figure out who's lying.
While these logic puzzles for adults can be solved through tricky math equations, they can also be thought up in your head. Don't worry, we start with simple logic puzzles and always provide explanations for the answer; But be warned: even after you get good at it, some of these difficult oneslogical puzzlesand the problems can stun you for hours. Ready to take on the challenge?
Simple logic puzzles
1. Logical puzzle:There are two ducks in front of a duck, two ducks behind a duck, and one duck in the middle. how many ducks are there
Answer:Three. Two ducks are in front of the last duck; the first duck has two ducks behind it; a duck is between the other two.
2. Logical puzzle:Five people ateapples, A finished before B but behind C. D finished before E but behind B. What was the finishing order?
Answer:HANGER. To tidy up the first three, A landed in front of B but behind C, so CAB. So we know that D finished before B, so CABD. We know that E ended after D, so CABDE.
3. Logical puzzle:Jack looks at Anne. Anne looks at George. Jack is married, George is not, and we don't know if Anne is married. Does a married person consider a single person?
Answer:Yes indeed. If Anne is married then she is married looking at George who is single. When Anne is single, Jack, who is married, looks at her. In any case, the statement is correct.
4. Logical Puzzle:A man is 53Parishin your drawer: 21 identical blue, 15 identical black and 17 identical red. The lights are off and he is in complete darkness. How many socks does he have to take off to be 100% sure he has at least one pair of black socks?
Answer:40 socks. If he draws 38 socks (adding the top two amounts, 21 and 17), it's highly unlikely, but possible that they're all blue and red. To be 100% sure that he also has a pair of black socks, he has to take off two more socks.
5. Logical Puzzle:The day before yesterday, two days later, tomorrow is Saturday. What day is today?
Answer:Freitag🇧🇷 "The day after tomorrow" is today; "the day before two days after" is actually the day after. So if "the day after today is Saturday," then it must be Friday.
6. Logical Puzzle:This burning rope problem is a classic logic puzzle. They have two strings that take an hour to burn, but they burn at inconsistent rates. How to measure 45 minutes? (You can light one or both strings at one or both ends at the same time.)
Answer:Since they both burn unevenly, you can't just light one end of a string and wait until it's 75% done. But this is what you can do: light the first string on both ends and the other string on one end, all at the same time. It takes 30 minutes to burn the first string (even if one side burns faster than the other, it still lasts 30 minutes). The moment the first string comes out, light the other end of the second string. Since the elapsed time since the second rope burned was 30 minutes, the remaining rope also lasts 30 minutes; If you light it from both sides, that cuts in half to 15 minutes, giving you 45 minutes total.
Related:Knowledge questions for children
Lie or tell the truth logic puzzles
7. Logical Puzzle:You are at a fork in the road where one direction leads to the City of Lies (where everyone always lies) and the other to the City of Truth (where everyone always tells the truth). There's a person at the fork who lives in one of the towns, but you're not sure which one. What question could you ask the person to find out which road leads to the city of truth?
Answer:"Which way do you live?" Someone from the city of lies will lie and point to the city of truth; someone from the city of truth would tell the truth and also point to the city of truth.
8. Logical Puzzle:A girl meets a lion andEinhornin the forest. The lion lies every Monday, Tuesday andWednesdayand other days he speaks the truth. The unicorn lies on Thursdays, Fridays and Saturdays, and tells the truth on other days of the week. "Yesterday I lied," said the lion to the girl. "Me too," said the unicorn. What day is today?
Answer:Thursday. The only day they both tell the truth isDomingo🇧🇷 but today can't be a Sunday because the lion also speaks the truth on Saturday (yesterday). Day after day, the only day one of them lies and one of them tells the truth with those two statements is Thursday.
9. Logical Puzzle:There are three characters (Alex, Ben and Cody) one of which is a knight, a villain and a spy. The knight always tells the truth, the villain always lies, and the spy can either lie or tell the truth. Alex says, "Cody's a villain." Ben says, "Alex is a knight." Cody says, "I'm the spy." Who is the knight, who is the trickster and who is the spy?
Answer:We know Ben is not telling the truth because if he were there would be two riders; So Ben can be either the villain or the spy. Cody can't be the knight either, because then his statement would be a lie. So that must mean that Alex is the knight. Ben must therefore be the spy, since the spy sometimes tells the truth; Leaving Cody as a villain.
River crossing logic puzzle
10. Logical Puzzle:A farmer wants to cross a river and take oneLob, a goat and aKohl🇧🇷 He has a boat, but only the wolf, goat or cabbage fit in it. When the wolf and the goat are alone on a bench, the wolf eats the goat. When the goat and cabbage are alone on the beach, the goat eats the cabbage. How can the farmer get the wolf, the goat and the cabbage across the river without getting any food?
Answer:First, the farmer crosses the goat. The farmer returns alone and then crosses with the wolf but returns with the goat. So the farmer runs through the cabbage, leaves it with the wolf, and goes back alone to get the goat.
11. Logical Puzzle:Let's imagine we were in the metric system and using kilograms instead of pounds to give us an initial base number of 100. Four people (Alex, Brook, Chris and Dusty) want to cross a river in a boat that can only carry 100 kg. Alex weighs 90kg, Brook 80kg, Chris 60kg and Dusty 40kg and they have 20kg of supplies. How do they cross?
Answer:There might be a few variations that work, but here's one way: Chris and Dusty row (100kg together), Dusty returns. Alex paddles out and Chris returns. Chris and Dusty cross paths again, Dusty returns. Brook paddles out with the supplies (100kg total) and Chris returns. Chris and Dusty are paddling again.
12. Logical Puzzle:This famous river crossing problem is known as the "bridge and torch" puzzle. Four people walk across a bridge at night so they all need a flashlight but they only have one that only lasts 15 minutes. Alice can cross in one minute, Ben in two minutes, Cindy in five minutes and Don in eight minutes. No more than two people are allowed to cross at the same time; and when two cross each other, they must go at the pace of the slower person. How do they cross in 15 minutes?
Answer:Alice and Ben will cross first in two minutes, and Alice will go back alone with the torch in a minute. So the two slowest people, Cindy and Don, cross in eight minutes. Ben will be back in two minutes, and Alice and Ben will be back in two minutes. They just arrived in exactly 15 minutes.
Relatives: 101oddities
Deadly Decisions Logic Puzzles
13. Logical Puzzle:A crook plays Russian roulette with a six-shooter. He places a bullet, rotates the chambers, and shoots you, but no bullets come out. It gives you the chance to spin the chambers again before firing a second time. Should he turn again?
Answer:Yes indeed. Before it spins, there is a one in six chance that a bullet will be fired. Once it spins, one of those odds is eliminated, leaving a one in five chance and making a bullet more likely to be fired. Better turn again.
14. Logical Puzzle:Same situation but two balls are placed in consecutive chambers. Should you tell the villain to spin the chambers again?
Answer:Not. With two bullets, you have a two in six (or one in three) chance of being hit by a bullet before you fire the first time. Because we know the previous round was one of four empty chambers, that leaves four positions the gun could be in now, with only one followed by a bullet; Therefore, you have a one in four chance that the second shot will go off. Since one in four has a better chance than one in three, it shouldn't spin again.
15. Logical Puzzle:This can also fall into the lie/truth category. A man is caught on the king's estate. He is brought before the king for punishment. The king says, "You must make a statement to me. If it is true, you will be killed by lions. If wrong, you will be trampled to death by wild buffalo. I have to let you go The man was released anyway What was the man's statement?
Answer:"I will be killed if I step on a wild buffalo." This left the king perplexed because if it were true he would be killed by lions which would make the claim false. If it was a lie he would be killed by wild buffalo which would make it true. Since the king had no solution, he had to let the man go.
Hard logic puzzles for adults
16. Logical Puzzle:Susan and Lisa decided to play tennis against each other. They bet $1 on every game they play. Susan won three bets and Lisa won $5. How many games did they play?
Answer:Eleven. When Lisa lost three games to Susan, she lost $3 ($1 per game). So she had to recoup that $3 with three more games and then win another five games to make $5.
17. Logical Puzzle:If five cats can catch five mice in five minutes, how long does it take a cat to catch a mouse?
Answer:Five minutes. With the information we have, it would take a cat 25 minutes to catch all five mice (5x5=25). So if we work backwards and divide 25 by five, we have five minutes for a cat to catch each mouse.
18. Logical Puzzle:There's a barrel without a lid and some wine in it. "This wine barrel is more than half full," says the woman. "No, it's not," says the man. "It's less than half full." Without measuring instruments and without removing wine from the cask, how can they easily tell who is right?
Answer:Tilt the keg until the wine barely touches the rim of the keg. If the bottom of the keg is visible, it is less than half full. If the bottom of the barrel is still completely covered with wine, it is more than half full.
19. Logical Puzzle:There are three bags, each containing two marbles. Bag A contains two white marbles, Bag B contains two black marbles, and Bag C contains one white and one black marble. You choose a random bag and take a marble that is white. What is the probability that the leftover marble from the same bag is also white?
Answer:2 out of 3. You know you don't have bag B. But since Bag A has two white marbles, you could have picked either one; If you think of it as a total of four marbles from bags A and C, three white and one black, you have a better chance of picking up another white marble.
20. Logical Puzzle:Three men are lined up one behind the other. The taller man is in the back and he can see the heads of the two in front of him; the middleman can see the only man in front of him; The man in front can't see anyone. They are blindfolded and hats are placed on their heads, chosen from three black hats and two white hats. The two extra hats are hidden and the blindfolds are removed. The tallest man is asked if he knows the color of the hat he is wearing; he no. The agent is asked if he knows; he no. But the man at the front, who doesn't see anyone, says he knows. How does he know and what color hat he wears?
Answer:Black. The man in the front knew he and the middle man weren't wearing white hats, or the man in the back would know he was wearing a black hat (since there are only two white hats). The frontman also knows that the middleman didn't see him wearing a white hat because if he did, the middleman would know from the taller man's response that he himself wears a black hat. So the frontman knows his hat has to be black.
21. Logical Puzzle:There are three boxes, one with apples, one with oranges and one with apples and oranges mixed. Each box is sealed and marked with one of three labels: apples, oranges, or apples and oranges. The label printer damaged and mislabeled all boxes. How could you just pick one fruit out of a box to find out what's in each box?
Answer:Choose a fruit from the Apples and Oranges box. If that fruit is an apple, you know the box must be labeled with apples because all the labels are wrong. So you know that the crate of apples must be oranges (if it were labeled apples and oranges, the crate of oranges would be labeled correctly, and we know it isn't), and the crate of oranges is apples and oranges. Alternatively, if you took an orange from the box marked apples and oranges, you know that the box marked oranges must be oranges, the box marked oranges must be apples, and the box marked apples must be apples and oranges.
The hardest logic riddles for adults
22. Logical Puzzle:A teacher writes six words on a blackboard: "Cat dog has maximum etiquette." She gives three students, Albert, Bernard, and Cheryl, each a piece of paper with a letter from one of the words on it. So she asks, "Albert, do you know the word?" Albert immediately replies yes. She asks, "Bernard, do you know that word?" He thinks for a moment and answers yes. Then she asks Cheryl the same question. She thinks and then answers yes. what is the word
Answer:Dog. Albert knows it immediately because it has one of the unique letters that occurs only once in each word: c o h s x i. So we know that the word is not "day". All of these single letters occur in different words, except "h" and "s" in "has", and Bernard can work out what the word is from the remaining single letters: t, g, h, s. This eliminates "max". and "dim". Cheryl can then reduce it in the same way. Since there is only one letter left, the letter 'd', the word must be 'dog'. (To learn more about this answer, watch the video below.)
23. Logical Puzzle:You have five boxes in a row numbered from 1 to 5, in which a cat is hidden. Every night it jumps to an adjacent crate, and everyMorningYou have the option to open a crate to find it. How do you win this hide and seek game?
Answer:Check boxes 2, 3 and 4 in order until you find it. Here's why: it's in an odd or even box. If it's in an even box (box 2 or 4) and you check box 2 and here it is, great; If not, you know he was in box 4, which means he'll be moving to box 3 or 5 the next night. Next morning check box 3; If it's not there, that means it was in box 5, so the next night it will be in box 4, and you've got it. If it was in an odd-numbered box to start (1, 3, or 5), you might not find it on the first round of checkboxes 2, 3, and 4. But if it is, you'll know that by night four it has to be in an even box (because it rotates every night: odd, even, odd, even) so you can start the process over again as above. This means if you tick boxes 2, 3, and 4 in that order, you'll find it in two rounds (one round of 2, 3, 4; followed by another round of 2, 3, 4). To learn more about this answer, watch the video below.
24. Logical Puzzle:The Monty Hall problem became famous when it was published in theHaltfrom the magazine"Ask Marilynin 1990, and it was so counterintuitive that everyone from high school students to leading math minds questioned the answer — but rest assured the solution is correct. Nominated for thelet's make a dealGame show host, the puzzle is this, you have three doors to choose from, one containing a car and the other two containing goats. After selecting one but not opening it, Monty, knowing where everything is, reveals the location of a goat behind one of the other two doors. Should you keep your original choice or change if you want the car?
Answer:you should switch At the beginning your choice is with a probability of one in three for the car; the two doors with goats contain 2/3 of the chance. But since Monty knows and shows where one of the goats is, that 2/3 chance now only depends on the third door (your choice keeps your original 1/3 chance; you chose a goat rather than you want to start with). So the odds are better if you switch.
Almost impossible logic puzzle for adults
25. Logical Puzzle:A variation of a lie/truth problem, this riddle is known as the hardest logic riddle of all time. You meet three gods on a mountain top. One always tells the truth, the other always lies, and the other tells the truth or happens to lie. We can call them True, False and Random. They understand English but answer in their own language with yes or there for yes and no - but you don't know which is which. You can ask each of the gods three questions (and you can ask the same god more than one question), and they will answer yes or there. What are the three questions you ask to find out who is who?
Answer:Before we get to the answer, let's think about onehypothetical questionYou know the answer, like "Two plus two is four?" Then phrase it by asking a built-in question: "If I asked you if two plus two equals four, would you answer yes?" If yes means yes, truth would answer yes, but so would false (he's lying always, so he would say yes even if he actually answered there). If yes means no, both would still answer yes - in this case, False would answer yes to the embedded question, but saying there for the general question would be the truth, so it says yes. (Random's answer wouldn't make sense because we don't know if he's lying or telling the truth.)
But what if you said, "If I asked you if two plus two equals five, would you answer yes?" If already means yes, Truth would answer from there, as would False; if yes means no, both would answer there as well. So you know that if the built-in question is correct, true and false always answer with the same word you use; If the embedded question is wrong, they always answer with the opposite word. They also know that they always answer each other with the same word.
With that in mind, ask the god in the center your first question: "If I were to ask if the god on my left is random, would you answer yes?" According to the above logic, if the god answers yes and you speak with True or False, you know that the embedded question is correct and the god on the left is Random. It's also possible for you to talk to Random; But you know no matter who you're talking to, it's the god on the rightnoCoincidentally. When the answer is there, the opposite is true and you know the God withinTo letit's not random. Then you can ask the God, which you definitely know isn't a random question, with the same structure: “If I asked you if you were the truth, would you say yes?” If they answer yes, you know you that you speak with the truth; If they answer that, you know you're talking to False. After identifying that God as True or False, you can ask that same God one final question to identify Random: "If I were to ask if the God in the middle is Random, would you say yes?" Through the process of elimination, you can They identify the ultimate god.
If you've made it this far, you're a true logic puzzle genius!
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