Spell Eighty

How can you spell eighty with only two letters?

A-T (pronounced eighty).

Posted in Brain Teasers

Four Cards

Four cards are placed in front of you on the table, each with a number on one side and a color on the other. The visible cards show 3, 8, red and brown. Which cards should you turn over in order to test the truth of the statement that if a card shows an even number on one face, then its opposite face is red?

four-cards

You’d need to turn over only the 8 and brown card. Only a card with an even number on one face and which is not red on the other face can invalidate the stated rule. If you turn over the 3 card and it’s not red, it doesn’t invalidate the rule, nor does turning over the red card and finding it has the label 3.

This test was devised by Peter Cathcart Wason and is known as the Wason selection task. Less than 10% of test subjects got it correct in two separate studies.

Posted in Brain Teasers

From Scraps to Pants

A tailor can make a pair of pants from the scraps left over from sewing up five pairs of pants. If he has twenty-five scraps, how many pairs of pants can he make?

Six pairs of pants. He can make five initially, but once he’s done making five pairs of pants, he’ll have five remaining sets of scraps, meaning he can make an additional pair of pants, totaling six.

Posted in Brain Teasers

One Two Six Sequence

What is the next number in this series?

1, 2, 6, 42, 1806, ___

To get the next number, multiply the previous number in the series by itself plus one:

n × (n + 1).

For example, to get 6, multiply 2 × (2 + 1)
To get 42 multiply 6 × (6 + 1)

Thus, 1806 × 1807 = 3263442

Posted in Brain Teasers
Tagged with

Starts and Ends with E

What starts with “e”, ends with “e” and has one letter in it?

Envelope. Eye is a potential alternative. When spoken out loud it sounds like a single letter (I).

Posted in Riddles

Cat-Related Phrases

What are these words or phrases, which contain the word cat?

A dreadful event (11 letters)
A robber who climbs walls (10 letters, 2 words)
A systematic list (7 letters)

Catastrophe
Cat Burglar
Catalog

Posted in Brain Teasers

The Start Of What You Might Conceive

I’m the start of whatever you might conceive.
Next I describe a Thanksgiving meal.
Last I transform to a state we all leave.

What am I?

begin, binge, being. Everything has a beginning, Thanksgiving dinner is known for being a meal of excessive consumption and the mortal state of being (or the state of a human being) is one which, for all our efforts to extend, will eventually end.

Posted in Riddles

Days Before August 17th

How many days before August 17th is it, if fifty days ago, it was four times as many days since March 30th?

18 days or July 30th.

17 August – 18 days = 30 July.
30 July – 50 days = 10 June.
10 June – 30 March = 72 days, which equals 4 × 18.

Posted in Brain Teasers

Julian and Penelope’s Marriage Ages

When Julian and Penelope met, one was half the others age plus seven years. Ten years later when they married, Penelope was thirty, but this time one was nine tenths the age of the other. How old was Julian? (No fractions or partial years, whole numbers only).

Julian was 27 when Penelope was 30.

Posted in Brain Teasers

Dancing All The Time

Moving to and fro,
Dancing all the time.
Only to be moved by others
To allow them to pass by.

What am I?

A door.

Posted in Riddles
Tagged with