The numbers must be in ascending order. This can be a fun one to have people work out in person, as they test out three-number series and you can tell them whether or not they satisfy the pattern.
A windmill. The typical windmill, like the ones Don Quixote chased, have four vanes or sails. You might even say they look like wings. Windmills don’t have emotions, so they can’t laugh or cry. And since they don’t have actual wings, windmills don’t get off the ground. A well-oiled little bugger won’t make a peep.
They are the origins of the names of each day of the week.
Sunday – Sun day. Monday – Moon day. Tuesday – Tiw’s or Týr’s day, the god of single combat, son of Odin. Wednesday – Woden’s or Odin’s day, god of poetry and of the dead. Thursday – Thor’s day, god of thunder, son of Odin. Friday – Frigg’s day, goddess of the clouds, wife of Odin. Saturday – Saturn’s day, god of fertility and agriculture.
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?
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.