Logic riddles

logic

Gambling house

Even though the odds are always in favor of the gambling house, why does the establishment insist on a house limit on stakes?
Every casino in the world would go bankrupt without a house limit on stakes. Without it, gamblers would keep doubling their stakes until they won. No matter how bad a losing streak they were on, they would eventually win.
93.22 %
37 votes

logic

Lost in the desert

Jack and Joe were on vacation and driving along a deserted country road from the town of Kaysville to the town of Lynnsville. They came to a multiple fork in the road. The sign post had been knocked down and they were faced with choosing one of five different directions. Since they had left their map at the last gas station and there was no one around to ask, how could Jack and Joe find their way to Lynnsville?
They need to stand the signpost up so that the arm reading Kaysville points in the direction of Kaysville, the town they had just come from. With one arm pointing the correct way, the other arms will also point in the right directions.
93.84 %
41 votes

logicmathshort

Really hard algebra puzzle

2+3=8, 3+7=27, 4+5=32, 5+8=60, 6+7=72, 7+8=? Solve it?
98 2+3=2*[3+(2-1)]=8 3+7=3*[7+(3-1)]=27 4+5=4*[5+(4-1)]=32 5+8=5*[8+(5-1)]=60 6+7=6*[7+(6-1)]=72 therefore 7+8=7*[8+(7-1)]=98 x+y=x[y+(x-1)]=x^2+xy-x
89.33 %
39 votes

logicprobability

Live or die probability puzzle

Hussey has been caught stealing goats, and is brought into court for justice. The judge is his ex-wife Amy Hussey, who wants to show him some sympathy, but the law clearly calls for two shots to be taken at Hussey from close range. To make things a little better for Hussey, Amy Hussey tells him she will place two bullets into a six-chambered revolver in successive order. She will spin the chamber, close it, and take one shot. If Hussey is still alive, she will then either take another shot, or spin the chamber again before shooting. Hussey is a bit incredulous that his own ex-wife would carry out the punishment, and a bit sad that she was always such a rule follower. He steels himself as Amy Hussey loads the chambers, spins the revolver, and pulls the trigger. Whew! It was blank. Then Amy Hussey asks, 'Do you want me to pull the trigger again, or should I spin the chamber a second time before pulling the trigger?' What should Hussey choose?
Hussey should have Amy Hussey pull the trigger again without spinning. We know that the first chamber Amy Hussey fired was one of the four empty chambers. Since the bullets were placed in consecutive order, one of the empty chambers is followed by a bullet, and the other three empty chambers are followed by another empty chamber. So if Hussey has Amy Hussey pull the trigger again, the probability that a bullet will be fired is 1/4. If Amy Hussey spins the chamber again, the probability that she shoots Hussey would be 2/6, or 1/3, since there are two possible bullets that would be in firing position out of the six possible chambers that would be in position.
90.26 %
43 votes

logicmath

Equation riddle

If, Fernando + Alonso + McLaren = 6 Fernando x Alonso = 2 Alonso x McLaren = 6 Then, McLaren x Fernando =?
3 Explanation: Fernando + Alonso + McLaren = 6 Fernando x Alonso = 2 Alonso x McLaren = 6 Given. Fernando x Alonso = 2 Alonso x McLaren = 6 Rewriting Both equations in terms of Alonso, Fernando = 2/Alonso McLaren = 6/Alonso Replacing above values in equation "Fernando + Alonso + McLaren = 6" 2/Alonso + Alonso + 6/Alonso =6 (2 + Alonso^2 + 6)/Alonso = 6 8 + Alonso^2 = 6Alonso Alonso^2 - 6Alonso + 8 = 0 (Alonso - 4) (Alonso - 2) = 0 Therefore; Alonso = 4 or 2 Let's take value of Alonso as 2 Fernando = 2/2 = 1 McLaren = 6/2 = 3 Therefore; McLaren x Fernando = 3 x 1 = 3
90.47 %
44 votes

logicmath

Two coins

If you have two coins which total 35 cents and one of the coins is not a dime, what are the two coins?
A quarter and a dime. One coin is not a dime, but the other one is.
93.05 %
36 votes

cleanlogic

King's daughter

A young peasant wanted to marry the king's daughter. The king didn't like the idea of his daughter marrying a peasant, but he wanted to appear fair in front of his subjects. The king said that he would put two pieces of paper into a hat, one reading "exile" and the other reading "marriage". Later that day, the peasant overheard the king saying that both pieces of paper would read "exile", thus ensuring that the peasant would be out of his way for good. The peasant remained undaunted and, as arranged, arrived at the king's court where a large crown gathered for the big event. The peasant then did something that assured him the hand of the king's daughter. What did he do?
The peasant picked one of the pieces of paper and tore it up. He then asked the kind to show him the other piece of paper which, of course, said EXILE. The king, not wishing to appear fraudulent in front of his subjects, granted that the piece of paper the peasant had picked must have said MARRIAGE.
94.11 %
43 votes

logicmystery

A mysterious death

Dave and Brad, two popular politicians, met at a club to discuss the overthrow of their party leader. They each ordered a vodka on the rocks. Brad downed his and ordered another. He then drank his second in a gulp and decided to wait before he ordered a third. Meanwhile, Dave, who was sipping his drink, suddenly fell forward dead. Both men were setup for an assassination. Why did Dave die and Brad live?
Both Dave and Brad were given drinks with poisoned ice cubes. Brad drank his drinks so quickly that the ice didn't have time to melt and release the poison.
85.29 %
57 votes

logicmystery

Kidnapped kid

A rich man's son was kidnapped. The ransom note told him to bring a valuable diamond to a phone booth in the middle of a public park. Plainclothes police officers surrounded the park, intending to follow the criminal or his messenger. The rich man arrived at the phone booth and followed instructions but the police were powerless to prevent the diamond from leaving the park and reaching the crafty villain. What did he do?
This is a true story from Taiwan. When the rich man reached the phone booth he found a carrier pigeon in a cage. It had a message attached telling the man to put the diamond in a small bag which was around the pigeon's neck and to release the bird. When the man did this the police were powerless to follow the bird as it returned across the city to its owner.
78.87 %
63 votes

cleanlogicshort

Party magician

Imagine John, a party magician, is carrying three pieces of gold each piece weighing one kilogram. While taking a walk he comes to a bridge which has a sign posted saying the bridge could hold only a maximum of 80 kilograms. John weighs 78 kilograms and the gold weighs three kilograms. John reads the sign and still safely crossed the bridge with all the gold. How did he manage this?
John is a juggler. When he came to the bridge he juggled the gold, always keeping one piece in the air.
87.19 %
44 votes