Best difficult riddles

logicstorycleverclean

A fancy restaurant in New York was offering a promotional deal. A married couple could eat at the restaurant for half-price on their anniversary. To prevent scams, the couple would need proof of their wedding date. One Thursday evening, a couple claimed it was their anniversary, but didn't bring any proof. The restaurant manager was called to speak with the couple. When the manager asked to hear about the wedding day, the wife replied with the following: "Oh, it was a wonderful Sunday afternoon, birds were chirping, and flowers were in full bloom." After nearly 10 minutes of ranting, she comes to tell him that today was their 28th wedding anniversary. "How lovely", the manager said, "However, you do not qualify for the discount. Today is not your anniversary, you are a liar". How did the manager know that it wasn't their anniversary?
The calendar repeats itself every 28 years. So, if they were married on a Sunday 28 years ago, the day they were at the restaurant would also have to be a Sunday. Since it was a Thursday, the manager knew they were lying, and abruptly kicked them out of his restaurant.
75.92 %
65 votes
cleansimpleinterview

A man is sitting in a pub feeling rather poor. He sees the man next to him pull a wad of £50 notes out of 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, 'OK, 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?
Happy Birthday.
75.85 %
109 votes
what am I

A name of an animal minus the first three letters plus a flat piece of wood. What am I ?
(MON) KEY + board= Keyboard
75.77 %
44 votes
logicclever

A teacher decides to give a pop quiz one day but all of her students refuse to take the quiz thinking that the teacher will call off the quiz. She can give only one of these students a detention for skipping the quiz. All of the students know each other's names and if a student knows he/she is getting a detention they take the quiz. How can she threaten her students with the single detention so they all take the quiz?
She tells them that she will give the student who skips the quiz whose name comes first alphabetically a detention. This student won't skip because they know they are getting a detention if they do. The next person alphabetically will then know that they will get a detention so they won't skip either, and so on.
75.69 %
89 votes
cleanfunnylogiclove

A doctor and a bus driver are both in love with the same woman, an attractive girl named Sarah. The bus driver had to go on a long bustrip that would last a week. Before he left, he gave Sarah seven apples. Why?
An apple a day keeps the doctor away!
75.62 %
210 votes
logiccleansimple

A farmer challenges an engineer, a physicist, and a mathematician to fence off the largest amount of area using the least amount of fence. The engineer made his fence in a circle and said it was the most efficient. The physicist made a long line and said that the length was infinite. Then he said that fencing half of the Earth was the best. The mathematician laughed at the others and with his design, beat the others. What did he do?
The mathematician made a small circular fence around himself and declared himself to be on the outside.
75.57 %
59 votes
logicclean

You have twelve balls, identical in every way except that one of them weighs slightly less or more than the balls. You have a balance scale, and are allowed to do 3 weighings to determine which ball has the different weight, and whether the ball weighs more or less than the other balls. What process would you use to weigh the balls in order to figure out which ball weighs a different amount, and whether it weighs more or less than the other balls?
Take eight balls, and put four on one side of the scale, and four on the other. If the scale is balanced, that means the odd ball out is in the other 4 balls. Let's call these 4 balls O1, O2, O3, and O4. Take O1, O2, and O3 and put them on one side of the scale, and take 3 balls from the 8 "normal" balls that you originally weighed, and put them on the other side of the scale. If the O1, O2, and O3 balls are heavier, that means the odd ball out is among these, and is heavier. Weigh O1 and O2 against each other. If one of them is heavier than the other, this is the odd ball out, and it is heavier. Otherwise, O3 is the odd ball out, and it is heavier. If the O1, O2, and O3 balls are lighter, that means the odd ball out is among these, and is lighter. Weigh O1 and O2 against each other. If one of them is lighter than the other, this is the odd ball out, and it is lighter. Otherwise, O3 is the odd ball out, and it is lighter. If these two sets of 3 balls weigh the same amount, then O4 is the odd ball out. Weight it against one of the "normal" balls from the first weighing. If O4 is heavier, then it is heavier, if it's lighter, then it's lighter. If the scale isn't balanced, then the odd ball out is among these 8 balls. Let's call the four balls on the side of the scale that was heavier H1, H2, H3, and H4 ("H" for "maybe heavier"). Let's call the four balls on the side of the scale that was lighter L1, L2, L3, and L4 ("L" for "maybe lighter"). Let's also call each ball from the 4 in the original weighing that we know aren't the odd balls out "Normal" balls. So now weigh [H1, H2, L1] against [H3, L2, Normal]. -If the [H1, H2, L1] side is heavier (and thus the [H3, L2, Normal] side is lighter), then this means that either H1 or H2 is the odd ball out and is heavier, or L2 is the odd ball out and is lighter. -So measure [H1, L2] against 2 of the "Normal" balls. -If [H1, L2] are heavier, then H1 is the odd ball out, and is heavier. -If [H1, L2] are lighter, then L2 is the odd ball out, and is lighter. -If the scale is balanced, then H2 is the odd ball out, and is heavier. -If the [H1, H2, L1] side is lighter (and thus the [H3, L2, Normal] side is heavier), then this means that either L1 is the odd ball out, and is lighter, or H3 is the odd ball out, and is heavier. -So measure L1 and H3 against two "normal" balls. -If the [L1, H3] side is lighter, then L1 is the odd ball out, and is lighter. -Otherwise, if the [L1, H3] side is heavier, then H3 is the odd ball out, and is heavier. If the [H1, H2, L1] side and the [H3, L2, Normal] side weigh the same, then we know that either H4 is the odd ball out, and is heavier, or one of L3 or L4 is the odd ball out, and is lighter. So weight [H4, L3] against two of the "Normal" balls. If the [H4, L3] side is heavier, then H4 is the odd ball out, and is heavier. If the [H4, L3] side is lighter, then L3 is the odd ball out, and is lighter. If the [H4, L3] side weighs the same as the [Normal, Normal] side, then L4 is the odd ball out, and is lighter.
75.38 %
83 votes