In the bar (2)

You are on the Island of Zwrazr in the Logico archipelago where there are three types of people: Truth-speakers, who always speak the truth, Liars, who always lie, and Switchers, who alternate their sentences between speaking the truth and lying.

In the bar (2)^***/*****
In a bar, the barkeeper shows you to a table with three people: “That table over there, with three people, has exactly one representative of each of the three groups of people on our Island.”
You introduce yourself at the table and the only woman among them says:
My friend to the left of me is a Switcher
My friend to the right of me is a Switcher
What can you say about the barkeeper?

You can check your solutions here

The successor of the Sultan (2)

The sultan took the survivors of the first round one by one to a second room with three boxes, depicted below. One was made of bronze, one of silver, and the third of gold.

Test 2^***/*****
He told them: One of the three chests holds a treasure. And exactly one of the labels on the boxes is true. You must open one of the boxes. No doubt it will comfort you that the poison of the snakes in the other two boxes are Naja mortiferum, the toxin of which is extremely painful and deadly, but very fast working, so you won’t suffer very long.

Which box should the candidate open?

New puzzles are published at least once a month on Fridays. Solutions are published after one or more weeks. You are welcome to remark on the difficulty level of the puzzles, discuss alternate solutions, and so on. Puzzles are rated on a scale of 1 to 5 stars. You can check your solution here.

The successor of the Sultan (1)

It was already known that the Sultan of Buhrundipur was a cruel men. It is only through recent research that we learnt how cruel. We already knew that the empire collapsed after his demise. He put all candidates whom he considered to be a possible successor through a series of tests, which have only now come to light.

Test 1^**/*****
There are 3 boxes, each with a label. One box holds a treasure, two boxes hold a deadly poison which is released when opening the box. One label tells the truth, the other two are lies.
Box 1: “This box holds a poison”
Box 2: “This box holds a treasure”
Box 3: “The label on box 2 is false”

Which box should the candidate open?

New puzzles are published at least once a month on Fridays. Solutions are published after one or more weeks. You are welcome to remark on the difficulty level of the puzzles, discuss alternate solutions, and so on. Puzzles are rated on a scale of 1 to 5 stars. You can check your solution here.

Knight or knave?

The well-known explorer Kickedoutofbed arrived a his first island in the Logico archipelago. He had been warned that there were two types of natives: Knights, who always speak the truth, and knaves, who always lie.

1) knight or knave?^**/*****
He met his first native right on the beach. Of course he was curious if the native was a knight or a knave, so he asked:
“Are you a knight or a knave?”
The answer came without hesitation:
“Yes, I am.”

Which of the two types is the native?

You can check your solutions here

New puzzles are published at least twice a month on Fridays.

Truth or Lie?

I have posted a small series of truth or lie puzzles at this blog, you can find them here.

This week I have just a link for you. Russian born USA mathematician published a nice puzzle here. It’s a toughy.

In the bar with Truth-speakers, Switchers and Liars

The remote island of Zwrazr in the Logico archipelago is inhabited by three types of people: Truth-speakers, Liars, and Switchers. Truth-speakers always speak the truth, Liars always lie, and Switchers alternate their sentences between a true sentence and a lie.

After the previous puzzle you are thirsty, and the truth-speaker brings you to a bar close to the harbor. He points at a table with three people, and tells you they are a Truth-speaker, a Liar and a Switcher. He tells you the three people are called Al, Bill and Cindy.
Al says:
Bill is a Liar
Cindy is a Liar

Bill tells you:
Al is a liar
Cindy is a switcher

Cindy sips her cola and thoughtfully says:
Bill is a truth-speaker.

So, who is who?

You can check your solutions here

New puzzles are published at least twice a month on Fridays.

Truth-speakers, Switchers and Liars at the table in the restaurant

In the restaurant^***/*****
The remote island of Zwrazr in the Logico archipelago is inhabited by three types of people: Truth-speakers, Liars, and Switchers. Truth-speakers always speak the truth, Liars always lie, and Switchers alternate their sentences between a true sentence and a lie.

In a restaurant, a group of natives are sitting at a circular table.
They take turns to say: the person to my left is a Switcher.
After that, they take turns, starting with the same person, to say: the person to my left is a Liar

What can you say about their type? How many are Truth-speakers? How many are Switchers? How many of them are Liars?

You can check your solution here

New puzzles are published at least twice a month on Friday. You are welcome to remark on the difficulty level of the puzzles, discuss alternate solutions, and so on. Puzzles are rated on a scale of 1 to 5 stars.

Truth-speakers, Liars and Switchers

The remote island of Zwrazr in the Logico archipelago is inhabited by three types of people: Truth-speakers, Liars, and Switchers. Truth-speakers always speak the truth, Liars always lie, and Switchers alternate their sentences between a true sentence and a lie.

As you arrive on the island, a group of three natives comes to greet you. According to tradition, the group consist of one representative of each group. Luckily for you, they introduce themselves:

• The left one says: I am a truth speaker
• The middle one says: I am a liar
• The one on the right says: I am a switcher

So now you know who is who, don’t you?

You can check your solutions here

New puzzles are published at least twice a month on Fridays. Solutions are published after one or more weeks. You are welcome to remark on the difficulty level of the puzzles, discuss alternate solutions, and so on. Puzzles are rated on a scale of 1 to 5 stars.

On the isle of Uauau

On the isle of Uauau the natives speak the truth on one day and lie on the next. On his or her “truth-day”, the man or woman will always speak the truth, and on their “lie-days” they will always lie. As a further complication, their truth days and lie-days are not synchronized, what is a truth day for one of them can be a lie day for his neighbor, father, brother or friend.

1) Today is a truth-day for me^*/*****
You meet a native who says: “Today is my truth day”. Can you conclude if he has a truth-day or not?

You can check your solutions here

2) Yesterday^*/*****
On Friday you meet a native who tells you: “Thursday is one of my lie-days”. Can you conclude if the native is speaking the truth or not?

You can check your solutions here

3) Different truth-days^**/*****
You meet two natives. One of them tells you:
“My friend and I have different Truth-days. Today is my friend’s lie-day.”
Does at least one of them have a lie-day?

You can check your solutions here

4) Friday(1)^***/*****
You meet two natives, let’s call them A and B as their real names are hard to pronounce. A says:
(1) My friend and I have the same truth-days.
(2) Last Friday my friend had a lie-day.
Does A speak the truth?

You can check your solutions here

5) Friday(2)^***/*****
You meet two natives on a Friday. For a change, let’s call them A and B, as their names are hard to remember. A says:
Yesterday I would have said that Friday is B’s truth-day.
Does B have a truth-day today?

You can check your solutions here

How many?

1) The logicians club^**/*****
Yesterday I visited a club of logicians. It’s a very special club, only trained logicians are admitted as members. During the club meetings, all members are required to speak the truth the entire evening, or to lie the entire evening. All members were seated around the circular table, truth tellers and liars alternating. I was not a member and watched from a distance. The president of the club welcomed all the members, and especially me as a guest.
He also explained some more rules which I admit I have quite forgotten. One part of the evening consisted of questions the members asked about the rules, while another topic were the finances.
At the end of the meeting, I asked the president how many members this club had. He happily told me that all 20 members had been present. When I was about to leave, I suddenly realized that the president himself need be trusted, and asked the secretary if the president had spoken the truth.
“Oh no!” the secretary exclaimed. “You should not believe the president, tonight he was a notorious liar! At this evening’s meeting, all 21 members were present!”

Whom should I believe? And why?

The puzzle above comes from “Denken als Spiel”, by Ernst Hochkeppel, one of the earliest puzzle books I obtained.

You can check your solutions here

2) The party^***/*****
Once there was a party where everybody with 100 people. Everybody shook hands with a number (some or all) of other people. Everybody present was either a liar (someone who always lies) or a Truthteller (someone who always speaks the truth).
When leaving the party, everybody was asked with how many Truthtellers he or she had shaken hands with. All answers 0, 1, 2, etc till 99 occurred exactly once.

How many Truthtellers were at the party?
This puzzle can also be watched as a video by Mindyourdecisions on youtube.

You can check your solutions here

New puzzles are published at least twice a month on Friday. Solutions are published after one or more weeks. You are welcome to remark on the difficulty level of the puzzles, discuss alternate solutions, and so on. Puzzles are rated on a scale of 1 to three stars.