The barber paradox – Solution

Suppose someone, let's call them John, has been found who wants to take on the role of national barber of Giwi. According to the law, John should be male. The law also states that all men have to get a shave at least once a week. so, John has to get a shave at least...

The barber paradox offered by Bertrand Russell

Consider the following variation on Russell's paradox. On the fictitious island nation of Giwi, very man has to get a shave at least once a week. This is prescribed by law. The can shave themselves or have someone else, for example the national barber, do the job....

Play Thinks

Ivan Moscovich was a designer and commercial developer of games, toys and puzzles. Having survived two concentration camps, he was liberated by British troops in 1945 and was sent to Sweden for recuperation before returning home.After finishing his university studies...

Nob’s number puzzle – Solution

At first sight, the puzzle seems to be rather easy. Looking at the first circles on the top: 99 and 72 pointing to 27, it makes sense to assume the following pattern: 92 - 72 = 27. The same pattern continues following the next few circles down the line: 45 - 27 = 18...

Four people on a rickety bridge – Solution

The initial solution most people come up with is the most obvious one: to use the fastest person, in our family, son Ben, to accompany his family members over the bridge one by one and to go back with the torch each time. This would take 10 + 1 + 5 + 1 + 2 = 19...

Nob’s number puzzle

Child psychologists have long since recognised that children learn through games and play. Being in control in play helps them to learn to manage their feelings and when children make or build things in their play, the are building skills and confidence in themselves...

Four people on a rickety bridge

When I turned BBC news on this morning, the first words I heard were 'emotional well-being' and 'cognitive decline'. Research has shown that a dexterous brain makes for happier, healthier people in general. Brain teasers and logic puzzles are one way to boost our...

Articles Brain Teasers

The barber paradox – Solution

Suppose someone, let's call them John, has been found who wants to take on the role of national barber of Giwi. According to the law, John should be male. The law also states that all men have to get a shave at least once a week. so, John has to get a shave at least...

The barber paradox offered by Bertrand Russell

Consider the following variation on Russell's paradox. On the fictitious island nation of Giwi, very man has to get a shave at least once a week. This is prescribed by law. The can shave themselves or have someone else, for example the national barber, do the job....

Play Thinks

Ivan Moscovich was a designer and commercial developer of games, toys and puzzles. Having survived two concentration camps, he was liberated by British troops in 1945 and was sent to Sweden for recuperation before returning home.After finishing his university studies...

Nob’s number puzzle – Solution

At first sight, the puzzle seems to be rather easy. Looking at the first circles on the top: 99 and 72 pointing to 27, it makes sense to assume the following pattern: 92 - 72 = 27. The same pattern continues following the next few circles down the line: 45 - 27 = 18...

Four people on a rickety bridge – Solution

The initial solution most people come up with is the most obvious one: to use the fastest person, in our family, son Ben, to accompany his family members over the bridge one by one and to go back with the torch each time. This would take 10 + 1 + 5 + 1 + 2 = 19...

Nob’s number puzzle

Child psychologists have long since recognised that children learn through games and play. Being in control in play helps them to learn to manage their feelings and when children make or build things in their play, the are building skills and confidence in themselves...

Four people on a rickety bridge

When I turned BBC news on this morning, the first words I heard were 'emotional well-being' and 'cognitive decline'. Research has shown that a dexterous brain makes for happier, healthier people in general. Brain teasers and logic puzzles are one way to boost our...

Articles Brain Teasers

The barber paradox – Solution

Suppose someone, let's call them John, has been found who wants to take on the role of national barber of Giwi. According to the law, John should be male. The law also states that all men have to get a shave at least once a week. so, John has to get a shave at least...

The barber paradox offered by Bertrand Russell

Consider the following variation on Russell's paradox. On the fictitious island nation of Giwi, very man has to get a shave at least once a week. This is prescribed by law. The can shave themselves or have someone else, for example the national barber, do the job....

Play Thinks

Ivan Moscovich was a designer and commercial developer of games, toys and puzzles. Having survived two concentration camps, he was liberated by British troops in 1945 and was sent to Sweden for recuperation before returning home.After finishing his university studies...

Nob’s number puzzle – Solution

At first sight, the puzzle seems to be rather easy. Looking at the first circles on the top: 99 and 72 pointing to 27, it makes sense to assume the following pattern: 92 - 72 = 27. The same pattern continues following the next few circles down the line: 45 - 27 = 18...

Four people on a rickety bridge – Solution

The initial solution most people come up with is the most obvious one: to use the fastest person, in our family, son Ben, to accompany his family members over the bridge one by one and to go back with the torch each time. This would take 10 + 1 + 5 + 1 + 2 = 19...

Nob’s number puzzle

Child psychologists have long since recognised that children learn through games and play. Being in control in play helps them to learn to manage their feelings and when children make or build things in their play, the are building skills and confidence in themselves...

Four people on a rickety bridge

When I turned BBC news on this morning, the first words I heard were 'emotional well-being' and 'cognitive decline'. Research has shown that a dexterous brain makes for happier, healthier people in general. Brain teasers and logic puzzles are one way to boost our...