Albert and Bernard became friends with Cheryl, and they want to know when her birthday is. Cheryl gives them a list of 10 possible dates. May 15 May 16 May 19 June 17 June 18 July 14 July 16 Aug 14 Aug 15 Aug 17 Cheryl then tells Albert and Bernard separately the month and the day of her birthday respectively. Albert: I don’t know when Cheryl’s birthday is, but I know that Bernard does not know too. Bernard: At first I don’t know when Cheryl’s birthday is, but I know now. Albert: Then I also know when Cheryl’s birthday is. When is Cheryl’s birthday?

A grandfather is telling his grandson war stories. “At the end of World War 1, I was awarded for my bravery after saving a group of my men,” the grandfather says. “You see, we were fighting in northern France and one of our enemies threw a grenade at us. I managed to pick it up and throw it away before it exploded. So right after the war ended, a General gave me a sword, engraved with the words ‘Awarded for Bravery and Valor, A True Hero, World War 1′.” The grandson thinks about the story for a minute and then says “Grandpa, that story can’t be true!” How did the grandson know?

You have three boxes. One has only red marbles, one has only blue marbles and the third has an equal number of red and blue marbles. The labels on the boxes have intentionally been switched so that each box is now marked incorrectly. Your job is to relabel the boxes correctly. Of course you could just look in the boxes to find out which labels match, but can you do it without looking into each box? Reach into any one of the boxes and select one marble. Can you now correctly label all three boxes? If not, select a second marble from any box. What is the fewest number of marbles you need to inspect in order to correctly label each box?

You are on your way to visit your Grandma, who lives at the end of the valley. It’s her anniversary, and you want to give her the cakes you’ve made. Between your house and her house, you have to cross 5 bridges, and as it goes in the land of make believe, there is a troll under every bridge! Each troll, quite rightly, insists that you pay a troll toll. Before you can cross their bridge, you have to give them half of the cakes you are carrying, but as they are kind trolls, they each give you back a single cake. How many cakes do you have to leave home with to make sure that you arrive at Grandma’s with exactly 2 cakes?

A man was sitting at the bar feeling rather poor. He sees the man next to him pull out $50 note from his wallet. He turns to the rich man and says to him, “I have an amazing talent: I know almost every song that has ever existed!” The rich man laughs. The poor man says, “I am willing to bet you all the money you have in your wallet that I can sing a genuine song with a lady’s name of your choice in it.” The rich man laughs again and says, “Okay. How about my daughter’s name Joanna Armstrong-Miller?” The rich man goes home poor. The poor man goes home rich. What song did he sing?

A poor farmer went to the market to sell some peas and lentils. However, as he had only one sack and didn’t want to mix peas and lentils, he poured in the peas first, tied the sack in the middle, and then filled the top portion of the sack with the lentils. At the market a rich innkeeper happened by with his own sack. He wanted to buy the peas, but he did not want the lentils. Pouring the seed anywhere else but the sacks is considered soiling. Trading sacks is not allowed. The farmer can’t cut a hole in his sack. How would you transfer the peas to the innkeeper’s sack, which he wants to keep, without soiling the produce?

Two men ride their horses to the town blacksmith to ask for his daughter’s hand in marriage. To help decide who will get to marry her, the blacksmith proposes a very strange race: “You will race your horses down the mile-long road from here to to the center of town, and the man whose horse passes through city hall’s gates LAST will get to marry my daughter.” The men have no idea how to proceed, but after a few minutes of thinking, they come up with a great idea to abide by the blacksmith’s rules. 30 minutes later, one of the men is gloating, having won the daughter’s hand in marriage. What was the idea the men had?

A professor asked John to write down any multi-digit number. But, he put a condition, the number should not end with a zero. John put down the number 96452. Then the professor asked John to add up the five digits and subtract the total from the original number. John did and here is what he got: 96452 – 26 = 96426 The professor then asked John to cross out any one of the five digits and tell him the remaining numbers. John crossed out the 2 and told the professor the rest of the digits. John neither told the professor the original number nor what he had done with it. Yet, the professor told John the exact number he had crossed out. How is it possible?

Tom meets a new neighbour, Cheryl, next door to him. During the conversation with Cheryl, Tom asks her: “How many kids do you have”. “Three” replied Cheryl. Tom asked “How old are they?” Cheryl answered:”The product of their ages is 36. The sum of their ages are the same as my house number.” After some time Tom replied “I can’t figure it out. I don’t have enough information”. “My apologies, I forgot to tell you that my youngest child likes strawberry milk” replied Cheryl. Tom figured out their ages after her answer and Cheryl confirmed that he was right. How old are Cheryl’s children?

A king decided to let a prisoner try to escape the prison with his life. The king placed 2 marbles in a jar that was glued to a table. One of the marbles was supposed to be black and one was supposed to be blue. If the prisoner picked the blue marble, he would escape the prison with his life. If he picked the black marble, he would be executed. However, the king was very mean and he wickedly placed 2 black marbles in the jars without any blue marbles. The prisoner witnessed the king only putting 2 black marbles in the jars. The jars were not see-through, the jars were glued to the table and the prisoner was mute so he could not say anything. How did he escape with his life?

There are five people. One of them shot and killed one of the other five. Dan ran in the NY City marathon yesterday with one of the innocent men. Mike considered being a farmer before he moved to the city. Jeff is a topnotch computer consultant and wants to install Ben’s new computer next week. The murderer had his leg amputated last month. Ben met Jack for the first time six months ago. Jack has been in seclusion since the crime. Dan used to drink heavily. Ben and Jeff built their last computers together. The murderer is Jack’s brother. They grew up together in Seattle. Police arrived at the scene and immediately finds the murderer. Who was the murderer?

Harry went out to dinner with his friends Larry, Barry, and Gary. Harry sat across from Gary. At Gary’s right, opposite Barry, sat Larry. When the waiter came for their orders, Larry and Barry ordered steak. Gary chose fish, and Harry (who likes to be difficult) ordered like this: “Unless the man at the left of the man opposite the man who ordered fish is not having what the man across from the man at the right of the man at my left is having, then I’ll have what the man across from the man at the right of the man opposite me ordered. Otherwise, bring me the Fettuccine Alfredo.” Assuming “right” and “left” is from the viewpoint of the diners, what did Harry order?

There are 3 black hats and 2 white hats in a box. Three men A, B and 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. When A is asked if he knows the color of the hat he is wearing, he says no. When B is asked if he knows the color of the hat he is wearing he says no. When C is asked if he knows the color of the hat he is wearing he says yes and he is correct. What is the color of the hat C is wearing and how did he figure out the color of his hat? You can assume that all three men are perfect logicians.

Once upon a time there was a beautiful princess named Anna. Anna’s father, the King, wanted to be sure his daughter married an intelligent man. To test his daughter’s suitors the King hid Anna’s picture in one of three boxes. The suitor had to be able to select the box with Anna’s picture on one try and within twenty seconds. On the gold box was the message, “Anna’s picture is in this box”. The silver box had the message, “Anna’s picture is not in this box.” “Anna’s picture is not in the gold box” was written on the bronze box. The King would tell each suitor, “Only one of the three messages is correct.” Which box contained Anna’s picture?

There is a small town on the East Coast that has 2 barbershops each with a single barber, and on opposite sides of town. The barbershop in the good part of town is immaculate. The floors and windows are washed and the air is fresh. The barber is very friendly, always smiling, he has shined shoes, a nice head of hair, and a clean dress shirt. The barbershop in the bad part of town is a mess. The entire barbershop is covered with a layer of dirt, and the air smells of trash. The barber always has a frown on his face. His skin is oily, his hair is ragged, and there are always stains visible on his shirt. A man comes into town and hears of both barbershops and the man decides to go to the dirty barbershop in the bad part of town. Why does he do this?