**Continue reading the story**"Pancake sort"

## Monthly Archives for October, 2013

## Pancake sort

There are n pancakes of different diameters stacked on top of one another in a single stack. You want to sort the pancakes according to size so that the largest is at the bottom and the shortest is on top. At each step you can insert a spatula at any point between the pancakes and flip all pancakes above the spatula. Give a sorting algorithm …

## Cube surface

An ant is constrained to move along the walls, ceiling or floor (it cannot fly) of a cubical room. It starts in the middle of an edge of the cube. What is the distance of farthest point from the ant on the surface of the room (walls, floor, ceiling)?
- via Stack Exchange

## Coin game

Four coins are placed in 4 holes on the 4 edges of a square table. Each coin maybe either heads or tails. At any time, you are allowed to inspect two coins and replace each of them either heads up or tails up as per your choice. The coins are hidden in holes; there is no way of knowing whether a coin is heads or …

**Continue reading the story**"Coin game"## Dog tied

You tie a dog to a 12-foot rope and go to the shopping mall. When you return you find that the dog has eaten food that is 30 feet away. How?
- via Gpuzzles

## Alibi

You want to rob a house, but to establish an alibi, you want to make sure the burglar alarm goes off 2 hours after you rob the home. You are skilled enough to be able to steal without setting off the alarm. How can you arrange to have the alarm go on 2 hours after you are done robbing?
via Briangle

## Flip coins

There are 4 coins in a row. Each coin shows either heads or tails. You don't know in advance what each coin shows. You are blindfolded. Your goal is to make all coins face heads upwards. To achieve this, you keep flipping coins one at a time. If at any point of time all coins are heads, a machine beeps and you win. You want …

**Continue reading the story**"Flip coins"## A feasible explanation?

A 25 year old man was travelling with his father in a train.
He saw a tree and remarked, "A tree! Look father, a tree!"
Then he saw a road and remarked, "A road! Look father, a road!"
Then he saw a road and remarked, "A car! Look father, a car!"
Can you give a good explanation why he was behaving like a child? He was not mad.
- …

**Continue reading the story**"A feasible explanation?"