Three Switches and Three Blub Problem
Posted on December 29, 2011
(Last modified on August 7, 2020)
| 2 minutes
| Kinshuk Chandra
Problem: You are standing outside a room next to three switches, all of which are off. Each switch operates a different light bulb in the room. The room door is closed, so you cannot see which switch operates which bulb. You are only allowed to go into the room once. Determine which switch operates which bulb.
Solution: Stumped? The issue lies in the fact that there are only two possible positions for each switch (on or off), but three bulbs to identify.
[Read More]Flipping Coins on the table
Posted on December 20, 2011
(Last modified on August 7, 2020)
| 1 minutes
| Kinshuk Chandra
Problem: There are twenty coins sitting on the table, ten are currently heads and tens are currently tails. You are sitting at the table with a blindfold and gloves on. You are able to feel where the coins are, but are unable to see or feel if they heads or tails. You must create two sets of coins. Each set must have the same number of heads and tails as the other group.
[Read More]Reaching the door of Heaven
Posted on December 19, 2011
(Last modified on August 7, 2020)
| 2 minutes
| Kinshuk Chandra
Problem: A person dies, and he arrives at the gate to heaven. There are three doors in the heaven. one of them leads to heaven. another one leads to a 1-day stay at hell, and then back to the gate, and the other leads to a 2-day stay at hell, and then back to the gate. every time the person is back at the gate, the three doors are reshuffled. How long will it take the person to reach heaven?
[Read More]How can you properly devide the hotel charges?
Posted on December 18, 2011
(Last modified on August 7, 2020)
| 1 minutes
| Kinshuk Chandra
Problem: Three people check into a hotel. They pay $30 to the manager, and go to their room. The manager finds out that the room rate is $25 and gives $5 to the bellboy to return. On the way to the room the bellboy reasons that $5 would be difficult to share among three people so he pockets $2 and gives $1 to each person. Now each person paid $10 and got back $1.
[Read More]Passengers and Random Seats in Airplane
Posted on December 18, 2011
(Last modified on August 7, 2020)
| 1 minutes
| Kinshuk Chandra
Problem : 100 passengers are boarding an airplane with 100 seats.
Everyone has a ticket with his seat number. These 100 passengers boards the airplane in order.
However, the first passenger lost his ticket so he just took a random seat.
For any subsequent passenger, he either sits on his own seat or, if the seat is taken, he takes a random empty seat.
What’s the probability that the last passenger would sit on his own seat ?
[Read More]Find out the matching socks
Posted on December 18, 2011
(Last modified on August 7, 2020)
| 1 minutes
| Kinshuk Chandra
Problem : Michael have ten pairs of black socks, eight pairs of white socks and seven pairs of green socks. Everything is mixed in a draw. As there is no light he were not able to identify the color of the socks. How many of the socks did he want to take to match one pair ?
Solution: The answer is 4 since in worst case all 3 socks taken first will be different color then the 4th one would be repetition.
[Read More]Globe Walker
Posted on October 8, 2011
(Last modified on August 7, 2020)
| 2 minutes
| Kinshuk Chandra
Problem : How many points are there on the globe where, by walking one mile south, then one mile east and then one mile north, you would reach the place where you started?
Solution : The trivial answer to this question is one point, namely, the North Pole. But if you think that answer should suffice, you might want to think again!
Let’s think this through methodically. If we consider the southern hemisphere, there is a ring near the South Pole that has a circumference of one mile.
[Read More]Trains and Birds
Posted on October 8, 2011
(Last modified on August 7, 2020)
| 3 minutes
| Kinshuk Chandra
Problem : A train leaves City X for City Y at 15 mph. At the very same time, a train leaves City Y for City X at 20 mph on the same track. At the same moment, a bird leaves the City X train station and flies towards the City Y train station at 25 mph. When the bird reaches the train from City Y, it immediately reverses direction. It then continues to fly at the same speed towards the train from City X, when it reverses its direction again, and so forth.
[Read More]Gold for 7 days of work
Posted on October 8, 2011
(Last modified on August 7, 2020)
| 2 minutes
| Kinshuk Chandra
Problem : You’ve got someone working for you for seven days and a gold bar to pay them. You must pay the worker for their work at the end of every day. If you are only allowed to make two breaks in the gold bar, how do you pay your worker? (Assuming equal amount of work is done during each day thus requiring equal amount of pay for each day)
[Read More]The Ant Collision Problem
Posted on October 8, 2011
(Last modified on August 7, 2020)
| 2 minutes
| Kinshuk Chandra
Problem : There are three ants on different vertices of a equilateral triangle. What is the probability of collision (between any two or all of them) if they start walking on the sides of the triangle?
Similarly find the probability of collision with ‘n’ ants on an ‘n’ vertex polygon.
Solution : Note that equilateral has nothing to do with how they will collide. Also, ants are allowed to move on the sides only.
[Read More]