You are an expert on paranormal activity and have been hired to locate a spirit haunting an old resort hotel. Strong signs indicate that the spirit lies behind one of four doors. The inscriptions on each door read as follows:
Door A: It's behind B or C
Door B: Its behind A or D
Door C: It's in here
Door D: It's not in here
Your psychic powers have told you three of the inscriptions are false, and one is true. Behind which door will you find the spirit?
A small town is visited by an ice-cream truck every day. On the first day of February, the truck visits as usual and 5 children, one from each of the first 5 houses on the street buys an ice cream that is of the different flavor from each other along with a completely different topping.
Go through the details below and find out which child lives in which house and bought which ice-cream flavor with which topping:
1. Jim lives between the child who bought the Raspberry topping and the child who bought mango ice cream.
2. Joyce, whose house has an even number, bought the cherry topping. Nancy does not live next to Joyce.
3. The blackcurrant ice cream had no topping.
4. The child who lives in house number 2 had the butterscotch ice cream. The child in house number 3 did not have chocolate ice cream.
5. Mike had banana ice cream. He hates banana cherry.
6. The child who had the cashew topping lives in house number 5. Dustin does not live in house number 4.
Please note that the odd numbered houses and the even numbered houses are located on the exactly opposite sides of the street.
There are three light switches outside a room. One of the switches is connected to a light bulb inside the room.
Each of the three switches can be either 'ON' or 'OFF'.
You are allowed to set each switch the way you want it and then enter the room(note: you can enter the room only once)
Your task is to then determine which switch controls the bulb?
In a science lab, a petri dish hosts a healthy colony of yeast for an experiment. Now every minute, all the yeast cells divide into two. At noon, there was just a single cell of yeast and at 1:22, the Petri dish was half full. Can you calculate when the dish will be full of yeast?
10 people came into a hotel with 9 rooms and each guest wanted his own room. The bellboy solved this problem.
He asked the tenth guest to wait for a little with the first guest in room number 1. So in the first room, there were two people. The bellboy took the third guest to room number 2, the fourth to number 3, ..., and the ninth guest to room number 8. Then he returned to room number 1 and took the tenth guest to room number 9, still vacant.
How can everybody have his own room?
In 2007, a puzzle was released and $2 million prizes were offered for the first complete solution. The competition ended at noon on 31 December 2010, with no solution being found. Wiki