Made Of Wood But Can’t Be Sawed

What is made of wood but can’t be sawed?

Sawdust. It’s still made up of wood, but a saw will be of no use.

Posted in Riddles

Rebellious Randall

You’re waiting to board your flight at the airport with 99 other passengers, each with an assigned seat. All but one of the passengers will gladly sit in their designated seat. The only exception is Randall, a scoundrel who refuses to follow the rules. When he boards, he will choose a random, unoccupied seat.

If a rule-following passenger finds someone in their spot, they will choose another one at a random from the remaining unoccupied seats.

What is the probability that the last person to board the plane will sit in their proper seat?

The randomness stops as soon as someone else sits in Randall’s assigned seat. The chances of this happening range from 1 out of 99 to 1 out of 1 (when only one seat remains).

Thus, the probability of the last person sitting in their own seat can be calculated as 1/99 plus the sum of 2 to 98 of the formula 1 / n × (n + 1), which works out to 0.5, or 50%.

So there’s a 50% chance the last passenger will sit in their own seat thanks to Randall for screwing up order and procedure when boarding an aircraft.

Posted in Brain Teasers

A Precious Thing to Most

A precious thing to most,
In order to take it,
You must already have it.

What is it?

Life.

By Sef Daystrom

Posted in Riddles

Cops Close Cellar Corpse

Replace the letters with numbers to make this a valid mathematical equation.

    COPS
   CLOSE
  CELLAR
  CORPSE
    CASE
+ COLLAR
--------
  RECTOR
    2730
   29704
  249918
  278304
    2104
+ 279918
--------
  842678
Posted in Brain Teasers

Hello Father

A women and daughter walked into a restaurant. A man walked past and the women both said, “Hello, Father”. How is this possible?

The man was a priest.

Posted in Brain Teasers

Blast Paper Box Bank

Here are two groups of words.

A. blast, paper, box, bank
B. juice, bag, cradle, carpet

Which word from Group B belongs with the words from Group A?

Bag. All of the words in group A can begin with the word sand.

Posted in Brain Teasers

How Many Legs?

You walk into a room and see a bed. On the bed there are two dogs, four cats, a giraffe, five cows and a duck. There are also three chickens flying above the bed. How many legs are on the floor?

Since all of the animals are on the bed and no other furniture is mentioned in the room, there are six legs on the floor. Four legs from the bed and your own two legs as you stand in the room, amazed that someone managed to get so many animals onto a bed. And the ceiling must be vaulted to fit a giraffe. Also, who’s on cleanup duty?

Posted in Brain Teasers

Largest Product

Using all the digits from 1 to 7, what two numbers have the largest product? For example, 1234 x 567 = 699678 but you can do much better than that.

742 x 6531 = 4,846,002.

A similar problem can be found in L.A. Graham’s Ingenious Mathematical Problems and Methods with a range of 1 to 9, but the principle remains the same – the numbers with the smallest difference produce the largest product. You start out with the highest two digits, 7 and 6, then attach 5 and 4, putting the smaller of the two digits with the larger number, giving you 74 and 65. The next two highest digits are 3 and 2, giving you 742 and 653. Finally, you add the 1 to the lower number. Page 80 has the details of that solution.

Posted in Brain Teasers

A House With No Doors

I am in a house with no doors. There are people inside but give no reply. Who am I?

A fish. A fish bowl or aquarium is the fish’s house and the people inside are the decorative divers that offer no reply (one might ask how the fish knows, given that they aren’t a talkative bunch themselves).

Posted in Riddles

The Lonely King

King Ferdinand has no immediate living relatives and decides to hold a contest to find a worthy successor when he dies. He gives a seed to every contestant and explains that the person with the healthiest and most beautiful plant will win the throne.

When the final day of the contest arrives, the king finds hundreds of plants of all shapes and sizes. However, he ignores them and awards the throne to a girl holding a pot with only moist dirt.

Why did she win?

King Ferdinand was a kind and trusting man and wanted to be sure he found an honest heir. He gave small pebbles to all the contestants, claiming they were seeds. Therefore, any contestant with a plant had switched their “seed” in order to win. Everyone but the girl had been dishonest.

Posted in Brain Teasers