Four people need to cross a bridge in 17 minutes in the middle of the night. The bridge can only hold two or less people at any time and they only have one flashlight so they must travel together (or alone). The flashlight can only travel with a person so every time it crosses the bridge it must be carried back. Tom can cross in 1 minute, John can cross in 2 minutes, Sally can cross in 5 minutes, and Connor can cross in 10 minutes. If two people cross together they go as fast as the slower person.How can they cross the bridge in 17 minutes or less?
Tom wants to send Sally an expensive ring through the mail because they live thousands of miles apart. The only problem is that everything sent through the mail is stolen unless there is a lock put on it. Both Tom and Sally have plenty of locks and keys but they don’t have any of the same locks or keys.
How can Tom send Sally the ring without it getting stolen?
You have two coconuts and you want to find out how high they can be dropped from a 100 story building before they break. But you only have $1.40 and the elevator costs a dime each time you ride it up (it’s free for rides down).
How can you drop the coconuts to guarantee you will find the lowest floor they will break at, while starting and ending at floor 1?
Note: They break when dropped from the same height and they don’t weaken from getting dropped.
You are journeying in a far land searching for treasure when you come to a monk and a three-way fork in the road. The roads point North, East, and West. You can ask the monk one question. He will answer honestly yes, no, or just hum if he cannot answer the question.
What do you ask him to figure out the correct path?
What heavy seven letter word can you take two away from and be left with eight?
A young man walks through the forest. He comes to a bridge. In front of the bridge is a large man carrying an axe. The man says, “If you want to cross this bridge, you must tell me a statement. If the statement is true, you will be strangled to death. If the statement is false, your head will be chopped off.” A few minutes later, the young man crossed the bridge, while the large man stood pondering. What was the statement the young man had given?
A man is in court for killing his wife. In the closing statements the man’s lawyer surprises everyone when he announces “His wife is just missing. Everyone look at those doors. His wife is going to walk in those doors in about 30 seconds.”The entire court is silent and the jury stares at the door as the lawyer and the defendant stare at the jury. After a couple of minutes the lawyer says “See! If you were so sure he killed his wife, you wouldn’t be watching that door!”The jury goes into deliberation and comes back almost immediately with a guilty verdict.Why did the jury convict him?
There is a prison with 100 prisoners, each in separate cells with no form of contact. There is an area in the prison with a single light bulb in it. Each day, the warden picks one of the prisoners at random, even if they have been picked before, and takes them out to the room with the bulb. The prisoner will have the choice to flip the switch if they want. The light bulb starts off.
When a prisoner is taken into the area with the light bulb, he can also say “Every prisoner has been brought to the light bulb.” If this is true all prisoners will go free. However, if a prisoner chooses to say this and it’s wrong, all the prisoners will be executed. So a prisoner should only say this if he knows it is true for sure.
Before the first day of this process begins, all the prisoners are allowed to get together to discuss a strategy to eventually save themselves.
What strategy could they use to ensure they will go free?
You have died and find yourself faced with two doors. One door leads to heaven and the other door leads to hell, but you have no idea which goes where. In front of each door is a guard. You know that one guard always tells the truth and the other guard always lies, but you don’t know which is which. What one question can you ask one of the guards to find out which door leads to heaven?
You have a large number of friends coming over and they all get thirsty. Your first friend asks for 1/2 a cup of water. Your second friend asks for 1/4 a cup of water. Your third friend asks for 1/8 a cup of water, etc.
How many cups of water do you need to serve your friends?