It is an old maxim of mine that when you have excluded the
impossible, whatever remains, however improbable, must be the truth. Sherlock Holmes
You know my method. It is founded upon the observation of trifles. Sherlock Holmes
Inspector Martin: By George! How ever did you see that? Sherlock Holmes: Because I looked for it.
12 Balls and a Balance Scale
There are 12 balls of equal size and shape, but one is either lighter or heavier than the other 11.
Using no more than 3 balances, determine which ball is lighter or heavier.
T-town, F-town
You are standing at a fork in the road. One branch leads to T-town where everyone always tells the
truth, and the other branch leads to F-town where everyone always tells lies. The sign at the fork has obviously been
spun around many times, and someone is adjusting the sign yet again, but you don't know which town the person lives in.
What single question can you ask to determine with absolute certainty which road leads to T-town?
You finally arrive in T-town and discover it's market day and residents of both towns are present.
You hear the following comments:
Eeny: Meeny is a liar
Meeny: Eeny and Miney are liars
Miney: Moe is a liar
Moe: Only Meeny tells the truth
Who is from T-town and who is from F-town?
A T-town detective asks you to help identify a thief who is known to work alone. Before their
capture, three suspects swapped identity cards after obscuring their photos and physical descriptions. The ID cards do
reveal that 1 suspect is from T-town and the other 2 from F-town. The suspects make these statements:
#1: I'm innocent.
#2: I'm innocent.
#3: #2 did it.
Who's guilty?
Match Game
Twice Nothing
What's the temperature when it's twice as cold as 0 degrees?
Let There Be Light
Each of three switches controls a light in another room. You cannot see the lights when you are
able to see or touch the switches. You may only check the lights once. Determine which switch controls which light.
Too Many Relatives
Two fathers and two sons have a total of $30 between them. Each man has $10. Explain.
Is Half a Hole Better than None?
5 men dig 5 holes 5 feet deep in 5 hours. How long will it take one man to dig a half a hole?
More is Less
What five-letter word becomes shorter when you add two letters to it?
Silence is Golden
A closed bag contains 3 green hats and 2 red hats. Rudy, Trudy, Judy all close their eyes, take a
hat, put it on, and close the bag. When they open their eyes, Rudy looks at Trudy and Judy, but can't deduce the color
of his own hat. Trudy now tries to deduce her own hat's color but can't be certain. What color is Judy's hat?
4 and 7 Makes 9
How can you measure 9 cups of water using a 4-cup and 7-cup container?
A Classic Conundrum
If a centipede runs a 3-legged race in 8 minutes, how many oysters will it take to clip the whiskers off a walrus?
12 Balls and a Balance Scale
