Logic Riddles

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The Burglar

The Burglar

A burglar breaks into a house. In front of the house there is a doghouse with a name on it but it is crossed out. When he gets in he starts putting things in his bag.

Then he hears a voice, “God is watching you. God is watching you.”

He turns around and sees a parrot.

The man says, “Who are you?”

And the the parrot answers, “Edmund. Why?”

Then the parrot says, “Who names their little boy Edmund?”

Then, a voice says, the same one who named me God”

Who in the house is God and who was saying God is watching you?

The dog is god and the parrot was warning him.
Reveal Answer

The following sentence is false

The following sentence is false

The following sentence is false. The preceding sentence is true. Are these sentences true or false?

Neither, it's a paradox. If the first is true, then the second must be false, which makes the first false? it doesn't work.
Reveal Answer

The Decesion

The Decesion

You only have one match, and your electricy and heat are out of order, you have a kerosine heater, a fireplace, and a kerosine lamp. What do you lite first?

the match
Reveal Answer

Fork In the Road

Fork In the Road

A hiker comes to a fork in the road and doesn’t know which way to go to reach his destination. There are two men at the fork, one of whom always tells the truth while the other always lies. The hiker doesn’t know which is which, though. He may ask one of the men only one question to find his way. Which man does he ask, and what is the question?

Either man should be asked the following question: "If I were to ask you if this is the way I should go, would you say yes?" While asking the question, the hiker should be pointing at either of the directions going from the fork.
Reveal Answer

a school bus

a school bus

you buy a bus and then get into it and drive to the middle of town and pick up 7 people then you drive to a pub and pick up 19 people then you drive to your house and pick up 16 people. but tell me who was driving the bus?

the bus driver is you!
Reveal Answer

Half Full or Half Empty?

Half Full or Half Empty?

There is a barrel with no lid and some wine in it. “This barrel of wine is more than half full,” said Curly. “No it’s not,” says Mo. “It’s less than half full.”

Without any measuring implements and without removing any wine from the barrel, how can they easily determine who is correct?

Tilt the barrel until the wine barely touches the lip of the barrel. If the bottom of the barrel is visible then it is less than half full. If the barrel bottom is still completly coverd by the wine, then it is more than half full.
Reveal Answer

A Riddle Full of Puns

A Riddle Full of Puns

A man is in a legendary ‘no way in no way out’ room. He has a mirror and a table in the room. How does he get out?

He looks in the mirror and sees what he 'saw' and he takes the 'saw' and cuts the table in half. Two halves make a 'hole' and the man jumps throught the 'hole' to freedom.
Reveal Answer

Filling the room

Filling the room

An old man wanted to leave all of his money to one of his three sons, but he didn’t know which one he should give it to. He gave each of them a few coins and told them to buy something that would be able to fill their living room. The first man bought straw, but there was not enough to fill the room. The second bought some sticks, but they still did not fill the room. The third man bought two things that filled the room, so he obtained his father’s fortune. What were the two things that the man bought?

The wise son bought a candle and a box of matches. After lighting the candle, the light filled the entire room.
Reveal Answer

3 Switches

3 Switches

You are standing in front of a room with one lightbulb inside of it. You cannot see if it is on or off. Outside the room there are 3 switches in the off positions. You may turn the switches any way you want to. You stop turning the switches, enter the room and know which switch controls the lightbulb. How?

You turn 2 switches "on" and leave 1 switch "off" and wait about a minute. Then enter the room, but just before you enter, turn one switch from "on" to "off".

Once in the room, feel the lightbulb - if it is warm, but off, it has to be the last switch you turned off. If it is on, it has to be the switch left on. If it is cold and is off, it has to be the switch you left in the off position.
Reveal Answer

The Golden Apple

The Golden Apple

In marble hall as white as milk, lined with skin as soft as silk, within a fountain crystal clear, a golden apple does appear. No doors there are to this stronghold, yet thief’s break in and steal the gold. What it is?

an eeg
Reveal Answer

Fox, Goose and a Sack of Corn

Fox, Goose and a Sack of Corn

A man went on a trip with a fox, a goose and a sack of corn. He came upon a stream which he had to cross and found a tiny boat to use to cross the stream. He could only take himself and one other – the fox, the goose, or the corn – at a time. He could not leave the fox alone with the goose or the goose alone with the corn. How does he get all safely over the stream?

Take the goose over first and come back. Then take the fox over and bring the goose back. Now take the corn over and come back alone to get the goose. Take the goose over and the job is done!
Reveal Answer

Three hats

Three hats

The three wisest sages in the land were brought before the king to see which of them were worthy to become the king’s advisor. After passing many tests of cunning and invention, they were pitted against each other in a final battle of the wits.

Led blind-folded into a small room, the sages were seated around a small wooden table as the king described the test for them.

“Upon each of your heads I have placed a hat. Now you are either wearing a blue hat or a white hat. All I will tell you is this- at least one of you is wearing a blue hat. There may be only one blue hat and two white hats, there may be two blue hats and one white hat, or there may be three blue hats. But you may be certain that there are not three white hats.”

“I will shortly remove your blind folds, and the test will begin. The first to correctly announce the color of his hat shall be my adviser.  Be warned however, he who guesses wrongly shall be beheaded. If not one of you answers within the hour, you will be sent home and I will seek elsewhere for wisdom.”

With that, the king uncovered the sages’ eyes and sat in the corner and waited. One sage looked around and saw that his competitors each were wearing blue hats. From the look in their eyes he could see their thoughts were the same as his, “What is the color of my hat?”

For what seemed like hours no one spoke. Finally he stood up and said, “The color of the hat I am wearing is…”

..."Blue." At first glance, this problem appears to be impossible to solve. Contributing to this is the feeling that the King's only real clue- that there is at least one blue hat- is useless since the sage can clearly see that there are at least two blue hats.

Don't feel bad if you sat stuck on this one for a while: as the puzzle clearly states, so did the three wisest sages in the kingdom. It is this fact that allowed our sage to give his answer. In truth, any one of them would have come up with it, given enough time. Why?

Consider a situation which we knew was not the case- that there was exactly one blue hat. What would happen? There would be a split second of pondering by the person wearing that hat, and he would say "I am wearing a blue hat." No real puzzle there, but of course there wasn't just one blue hat. The important fact is that everyone knew there was not one blue hat. But more importantly than that, everyone knew, or could quickly figure out that everyone else knew this (by the fact that answer was did not come out in the first few seconds.)

This leaves everyone wondering, "Are there two or three blue hats?"

Consider this less obvious situation- that there were exactly two blue hats. This seems a very real possibility at first, after all, we can see exactly two blue hats. So everyone sits and thinks- for a little while. But if there are only two hats, then two people see one blue and one white hat. These two people will very quickly, by virtue of the other's silence, rule out the possibility that there is only one blue hat. One of these two lucky sages would cry blue within a few short minutes, if that long.

There is only one case which forces the three sages to sit in silence- three blue hats. Our sage, through his sharp wits was the first to reach this conclusion.
Reveal Answer