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.
Suppose you have twelve eggs and a balance scale. All of the eggs are identical except for one whose only difference is its weight. Using the scale only three times, determine which egg is the odd egg out and whether it is heavier or lighter than the other eggs.
Weigh four against four. If they’re equal, weigh three of them against three you haven’t weighed. If they balance too, weigh the last remaining egg against any of the others to see if it is lighter or heavier. If the three suspects are heavier, weigh one of them against another and the one that goes down is it. If they balance the remaining suspect is heavy. Use the same process if they’re lighter. If the initial four vs four don’t balance, weigh two heavy eggs and a light egg against one heavy egg, one light one and a known normal egg. If they balance weigh the remaining two light eggs against each other. If they balance the unweighed heavy egg is the odd one out. If the side with two heavy eggs goes down weigh them against each other. If they balance it is the light egg on the other side. If the other side goes down it is either because of one heavy egg on that side or because the one light egg on the other side is lighter than the rest. Weigh one of them against a known normal egg to determine which is true.
Emily passed away and it was a celebration of her life. Of course you don’t invite the deceased. Her body was in the casket, but Emily the person wasn’t there.
Fold the paper in half and make cuts that are almost entirely across the width of the paper. Switch between sides. When the paper is opened there will be a very large hole that you can climb through (carefully).
1. How do you put a giraffe into a refrigerator? 2. How do you put an elephant into a refrigerator? 3. The Lion King is hosting an animal conference. All the animals attend except one. Which animal doesn’t attend? 4. There is a river you must cross but it is used by crocodiles and you don’t have a boat. How can you cross safely?
1. Open the refrigerator, put the giraffe in and close the door. It’s not complicated. 2. Open the refrigerator, take out the giraffe, then put in the elephant and close the door. 3. The elephant. He’s still in the refrigerator. After all, you just put him there. 4. Jump into the river and swim across. The crocodiles are at the Lion King’s animal meeting. I admit, this is not a typical brain teaser, but it amused me.
Pencil lead. While modern pencils don’t contain lead, that’s still what we call the graphite compound. When real lead was used in pencils it was mined and nearly everyone has used a pencil at some point in their life.
Three travelers register at a hotel and are told that their rooms will cost $10 each so they pay $30. Later the clerk realizes that he made a mistake and should have only charged them $25. He gives a bellboy $5 to return to them but the bellboy is dishonest and gives them each only $1, keeping $2 for himself. So the men actually spent $27 and the bellboy kept $2. What happened to the other dollar of the original $30?
There is no missing dollar from the original $30 because after getting $1 back, the three travelers had paid a total of $27 for their room ($9 each), not $30. Out of that $27, the hotel has $25 and the clerk kept the remaining $2. If you still want to work from the original $30, the travelers have $3, the hotel has $25 and the bellboy has $2. The misleading part is adding the bellboy’s $2 to the $27, when in fact it should be subtracted.
More precious than gold, but cannot be bought, Can never be sold, only earned if it’s sought, If it is broken it can still can be mended, At birth it can’t start nor by death is it ended.
Friendship. It is more precious than gold to have a genuine friend, and true friendship cannot be bought or sold, only earned. When a friendship is broken it can be fixed and infants aren’t able to make friends until they’re older, but death can’t end it. Love doesn’t work as an answer because a friendship requires two people to interact, while parents love their children as soon as they’re born.
