Friday, September 30, 2005
Thursday, September 29, 2005
Wednesday, September 28, 2005
Tuesday, September 27, 2005
Monday, September 26, 2005
After teaching his class all about roman numerals (X = 10, IX=9 and so on) the teacher asked his class to draw a single continuous line and turn IX into 6. The only stipulation the teacher made was that the pen could not be lifted from the paper until the line was complete.
Posted by Michael Doherty at 9:42 AM
Sunday, September 25, 2005
A man was found murdered on Sunday morning. His wife immediately called the police. The police questioned the wife and staff and got these alibis:
The Wife said she was sleeping.
The Cook was cooking breakfast.
The Gardener was picking vegetables.
The Maid was getting the mail.
The Butler was cleaning the closet.
The police instantly arrested the murdered. Who did it and how did they know?
Posted by Michael Doherty at 11:18 AM
Saturday, September 24, 2005
Friday, September 23, 2005
A night shift guard, while on patrol at night, dreams that the king will die in a plane crash. He tells the king so in the morning, but the king tells him not to worry, and flies anyway. When he returns from his trip, he fires the night shift guard. Why does the king fire the night shift guard?
Posted by Michael Doherty at 8:05 AM
Thursday, September 22, 2005
Wednesday, September 21, 2005
Tuesday, September 20, 2005
Monday, September 19, 2005
Sunday, September 18, 2005
Two people are talking on the phone long distance. One is in an East Coast state of the U.S., the other is in a West Coast state of the U.S. The first asks the other, "What time is it?" He hears the answer and says, "That's funny. It's the same time here!" Neither one of them were mistaken about the time. How is this possible?
Posted by Michael Doherty at 2:55 PM
Saturday, September 17, 2005
Friday, September 16, 2005
1)If you were to put a coin into an empty bottle and then insert a cork in the bottle's opening, how could you remove the coin without taking out the cork or breaking the bottle?
2)Speaker: "Brothers and Sisters, I have none. But this man's Father is my Father's son."
Who is the speaker talking about?
Posted by Michael Doherty at 7:16 PM
Monday, September 12, 2005
An acquaintance tells you she has two children and you remember that one of them is a boy. Assuming every birth has an equal change of being male or female and you have no additional information about the children, what are the chances that the other child is also a male?
BTW, I'll be gone for a few days. In the meantime, please check out the rest of the site for more riddles, puzzles and other math/stat problems.
Posted by Michael Doherty at 10:33 PM
Amanda and Bob are twins; Amanda is the OLDER twin. Assume they were born immediately after each other, an infinitesimally small - but nonzero - amount of time apart. During one year in the course of their lives, Amanda celebrates her birthday two days AFTER Bob does. How is this possible?
Posted by Michael Doherty at 9:30 AM
Sunday, September 11, 2005
1) A black man, dressed in black, is crossing a road. He's blind and deaf. A truck is speeding towards him, with its lights turned off. The street lamps are also off and there's no moonlight. When the truck is about to hit the man, the driver hits the brakes and manages to stop just a few centimetres from him. How did the driver see the man?
2) A man walks into a bar and says "I want a coffee and a glass of water. But make sure the coffee is boiling hot and the water is ice-cold." The barman says "Sure thing, mr. fireman." The barman had never met him before. How did he know the man was a fireman?
Posted by Michael Doherty at 12:21 PM
Saturday, September 10, 2005
1) What is it that someone else has to take before you can get it?
2) What do you throw out when you want to use it, but take in when you don't want to use it?
3) The maker doesn't want it, the buyer doesn't use it and the user doesn't see it. What is it?
Posted by Michael Doherty at 2:11 PM
Thursday, September 08, 2005
A windowless room contains three identical light fixtures, each containing an identical light bulb. Each light is connected to one of three switches outside of the room. Each bulb is switched off at present. You are outside the room, and the door is closed. You have one , and only one, opportunity to flip any of the external switches. After this, you can go into the room and look at the lights, but you may not touch the switches again. How can you tell which switch goes to which light?
Hint: This one is easier than you think!
Posted by Michael Doherty at 10:03 PM
Wednesday, September 07, 2005
Tuesday, September 06, 2005
You are a prisoner sentenced to death. The Emperor offers you a chance to live by playing a simple game. He gives you 50 black marbles, 50 white marbles and 2 empty bowls. He then says, "Divide these 100 marbles into these 2 bowls. You can divide them any way you like as long as you use all the marbles. Then I will blindfold you and mix the bowls around. You then can choose one bowl and remove ONE marble. If the marble is WHITE you will live, but if the marble is BLACK... you will die."
How do you divide the marbles up so that you have the greatest probability of choosing a WHITE marble?
Posted by Michael Doherty at 9:43 PM
A group of 4 people, Andy, Brenda, Carl, & Dana, arrive in a car near a friend's house, who is having a large party. It is raining heavily, & the group was forced to park around the block from the house because of the lack of available parking spaces due to the large number of people at the party. The group has only 1 umbrella, & agrees to share it by having Andy, the fastest, walk with each person into the house, & then return each time. It takes Andy 1 minute to walk each way, 2 minutes for Brenda, 5 minutes for Carl, & 10 minutes for Dana. It thus appears that it will take a total of 19 minutes to get everyone into the house. However, Dana indicates that everyone can get into the house in 17 minutes by a different method. How? The individuals must use the umbrella to get to & from the house, & only 2 people can go at a time.
Posted by Michael Doherty at 11:12 AM
Monday, September 05, 2005
Saturday, September 03, 2005
Friday, September 02, 2005
Thursday, September 01, 2005
There are 3 black hats and 2 white hats in a box. Three men (we will call them A, B, & C) each reach into the box and place one of the hats on his own head. They cannot see what color hat they have chosen. The men are situated in a way that A can see the hats on B & C's heads, B can only see the hat on C's head and C cannot see any hats. A is asked first if he knows the color of the hat he is wearing, he says no. Then B is asked if he knows the color of the hat he is wearing he says no. Then C is asked if he knows the color of the hat he is wearing he says yes and he is correct. What color hat and how can this be?
Posted by Michael Doherty at 9:17 AM