There are 5 ships in a port.
The Greek ship leaves at six and carries coffee.
The ship in the middle has a black chimney.
The English ship leaves at nine.
The French ship with a blue chimney is to the left of a ship that carries coffee.
To the right of the ship carrying cocoa is a ship going to Marseille.
The Brazilian ship is heading for Manila.
Next to the ship carrying rice is a ship with a green chimney.
A ship going to Genoa leaves at five.
The Spanish ship leaves at seven and is to the right of the ship going to Marseille.
The ship with a red chimney goes to Hamburg.
Next to the ship leaving at seven is a ship with a white chimney.
The ship on the border carries corn.
The ship with a black chimney leaves at eight.
The ship carrying corn is anchored next to the ship carrying rice.
The ship to Hamburg leaves at six.
Which ship goes to Port Said? Which ship carries tea?
You and a friend are standing in front of two houses. In each house lives a family with two children.
"The family on the left has a boy who loves history, but their other child prefers math," your friend tells you.
"The family on the right has a 7-year old boy, and they just had a new baby," he explains.
"Does either family have a girl?" you ask.
"I'm not sure," your friend says. "But pick the family that you think is more likely to have a girl. If they do have a girl, I'll give you $100."
Which family should you pick, or does it not matter?
You should pick the house on the left. Specifically, there is a 2/3 chance that the family on the left has a girl, whereas there's only a 1/2 chance that the house on the right has a girl.
This is a very counterintuitive riddle. It seems like there should always be a 1/2 chance that a given child is a girl. And in fact there is. The key word there is "given". Because we are not asking about a "given" child for the house on the left. We are asking about what could be either child. Whereas for the house on the right, we are asking about a "given" child...specifically, we're asking about the younger child.
There are 3 possibilities for the children in the first house:
There is no "Girl, Girl" option because we know the house on the left has at least one boy. Since each of these 3 options is equally likely, and 2 of them have one girl, there is a 2/3 chance of there being a girl in the house on the left.
For the house on the right, because we already know the older child is a boy, there are only two possibilities:
And as we can see, there is a 1/2 chance for the house on the right having a girl.
Search for: Boy or Girl paradox
A frog is at the bottom of a well. It is a 30 foot climb to get out. Each morning, the frog jumps 3 feet up the path out, but each night, as it sleeps, it slips back 2 feet down.
Thus, at the beginning of the first day, the frog has 30 feet to go, at the beginning of the second day it has 29 feet to go, and so on.
How many days does it take the frog to get out of the well?
It takes 28 days for the frog to get out (it gets out on the morning of the 28th day).
This is because on the beginning of the 28th day, the frog has 3 feet left to travel. Because the frog jumps 3 feet forward each morning, it will jump out of the well on this day.
A crime has been committed at Freemont Street. The main suspect is a man named Sean Baker. It was said that a man had been walking along the pathway when he was suddenly shot in the stomach. The suspect had brown hair, blue eyes and wore a baggy Armani suit just like Sean Baker's. Sean was asked to tell the story right from the beginning. "Well," said Sean, "I was just hanging around the park when I saw this man walking along the pathway. Suddenly, a guy came up from behind him and shot him! I ran home as fast as I could. The policemen asked him to give a description of the murderer. "He had a red mustache, red hair and a baggy Armani suit on."
"I think this man is telling a lie," said one of the policemen. How did he know?
How can the murderer shoot him in the stomach if he came up behind the man?
A man entered his house and was about to hang up his coat when he heard his wife shout;
"No John! Don’t do it!"
There was a shot and he could hear his wife fall down. When he entered the kitchen he saw his wife and the gun lying on the floor. There was a police officer, a doctor, and a lawyer standing next to her. Peter immediately knew that the police officer had shot her.
But how did he come to know?
There is a row of five different color houses. Each house is occupied by a man of different nationality. Each man has a different pet, prefers a different drink, and smokes different brand of cigarettes.
The Brit lives in the Red house.
The Swede keeps dogs as pets.
The Dane drinks tea.
The Green house is next to the White house, on the left.
The owner of the Green house drinks coffee.
The person who smokes Pall Mall rears birds.
The owner of the Yellow house smokes Dunhill.
The man living in the centre house drinks milk.
The Norwegian lives in the first house.
The man who smokes Blends lives next to the one who keeps cats.
The man who keeps horses lives next to the man who smokes Dunhill.
The man who smokes Blue Master drinks beer.
The German smokes Prince.
The Norwegian lives next to the Blue house.
The man who smokes Blends has a neighbour who drinks water.
Who has fish at home?