In a supermarket, the first 25 customers of the day purchased an average of two items each.
After a further 15 customers, the average number of items purchased by each customer rose to eight.
What was the average number of items purchased by the last 15 customers only?
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.
A witch owns a field containing many gold mines. She hires one man at a time to mine this gold for her. She promises 10% of what a man mines in a day, and he gives her the rest. Because she is blind, she has three magic bags who can talk. They report how much gold they held each day, and this is how she finds out if men are cheating her. Upon getting the job, each man agrees that if he isn't honest, then he will be turned into stone. So around the witch's mines, many statues lay!
Now comes an honest man named Garry. He accepts the job gladly. The witch, who didn't trust him said, "If I wrongly accuse you of cheating me, then I'll be turned into stone."
That night, Garry, having honestly done his first day's job, overheard the bags talking to the witch. He then formulated a plan... The next night, he submitted his gold, and kept 1.6 pounds of gold. Later, the witch talked with her bags. The first bag said it held 16 pounds that day. The second one said it held 5 pounds. The third one said it held 2 pounds. Beaming, the witch confronted Garry. "You scoundrel, you think you could fool me. Now you shall turn into stone!" the witch cried. One second later, the witch was hard as a rock, and very grey-looking. How did Garry brilliantly deceive the witch?
Garry put 2 lbs. in bag #1. 3 lbs. were put in bag #2. 11 lb. were put into bag #3. He then put bag #2 into bag #3, and bag #1 into bag #2. The bags only felt the weight of the gold above it. Thus they inadvertently gave the message that 23 lbs. were taken.
Once there was an evil wizard. He took 3 women from their homes and turned them into rose bushes that looked exactly alike. He put them in his garden. One of the women had a husband and children and begged the wizard to let her see them. He agreed. At night he brought the woman to her house. In the morning he came and took her home. Next day the husband decided to go rescue her. So he snuck into the wizard's garden. He looked and looked at the 3 identical rose bushes trying to figure out which could be his wife. Suddenly he knew the answer and he took his wife home. How did he know which rose bush was his wife?
The wizard brought the rosebush to her home at night and returned her to the garden in the morning. Therefore, she was the only plant without dew.
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:
Younger Older
Girl Boy
Boy Girl
Boy Boy
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:
Younger Older
Girl Boy
Boy Boy
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 group of campers have been on vacation so long, that they've forgotten the day of the week. The following conversation ensues.
Darryl: "What's the day? I dont think it is Thursday, Friday or Saturday."
Tracy: "Well that doesn't narrow it down much. Yesterday was Sunday."
Melissa: "Yesterday wasn't Sunday, tomorrow is Sunday."
Ben: "The day after tomorrow is Saturday."
Adrienne: "The day before yesterday was Thursday."
Susie: "Tomorrow is Saturday."
David: "I know that the day after tomorrow is not Friday."
If only one person's statement is true, what day of the week is it?
There were two women, standing and facing the opposite ways. The first lady was facing south and the second lady was facing north. But, they could see each other. How is that possible?
A couple went on for a climbing trip. But only the husband returned from the vacation and said that his wife slipped off while climbing and died. On investigating, the local sheriff arrested him saying, 'Your travel agent called. You murdered your wife.'
The man did not inform anyone about the trip. Then how did the agent was so sure that it is a murder?
The man bought only one way ticket for his wife whereas he bought two way ticket for himself. It means that he was sure that he will be returning alone.
Mike was watching TV and all of a sudden he leaps to his feet and says, "That's Simon", pointing at someone who was at the screen.
Then his brother Mark comes in, looks at his brother, then looks back at the TV and says, "So it is."
How do they know Simon if they hadn't seen him before, no pictures, nothing?
Once upon a time there existed a temple in India which housed three identical idols which spoke to the devotees.
The idols were of – God of Truth, which always spoke the truth; God of Falsehood, which always lied; and God of Diplomacy which sometimes spoke the truth and at other times lied.
The pilgrims come from all parts of the world to get their questions answered by the Gods. But there was a problem. As the idols were indistinguishable, devotees were not sure from which idol to ask their questions and in turn they did not know which God has answered and whether to believe it or not.
Once a wise man visited the temple. He asked the question: "Which God is seated at the centre?" to all the three idols. The idol on the left, centre and right replied God of Truth, God of Diplomacy and God of Falsehood respectively. The wise man at once proclaimed that he had solved the mystery of the temple.
The idols from left to right are: God of Diplomacy, God of Falsehood, God of Truth.
The God of Truth is not seated on the left because he always speaks the truth whereas the idol on the left replied that the God of Truth is seated at the centre.
The God of Truth is also not seated in the centre as he always speaks the truth but the idol at the centre replied that the God of Diplomacy is seated at the centre.
Therefore, the God of Truth is seated on the right. As God of Truth is seated on the right, and he always speaks the truth, then the The God of Falsehood is seated at the centre. The God of Diplomacy is seated on the left and he has lied.
