King Akbar’s Line

One day the Great Akbar drew a line on the floor and asked his sage Birbal to shorten it without touching and ...

Personal mechanisms of sense creation

Sergey L. Markov.  Personal mechanisms of sense creation The paper discusses and analyzes the personal mechanisms of grasping and creating the new meanings. The system...
Cheops pyramid height 139 m

Measuring the Great Pyramid

While the famous Greek philosopher Thales of Miletus was in Egypt, he was asked to find out the height of the Great Cheops pyramid. How could...

Ship Ladder Puzzle

A ship is at anchor. Over its side hangs a rope ladder with rungs a foot apart. The tide rises at the...

A cup of tea

A man called to a waiter in a restaurant, "There's a fly in my tea!" The waiter replied, "I will bring you a fresh...

Detective’s find

Once a detective found a pipe, top hat, a scarf, a carrot and five pieces of coal lying together in the middle of a field. What is...

Time measurement task

A man has two ropes of varying thickness (Those two ropes are not identical, they aren’t the same density nor the same length nor...

Vigilant woman

A woman is sitting in her hotel room when there is a knock at the door. She opened the door to see a man...
Parable about Merchant

Fateful creative solution

One unfortunate merchant owed a large sum of money to a moneylender. The old, ugly moneylender proposed that he would forget the debt if...

The Light Switches Riddle

There are three switches outside a closed room. There are three lamps inside the room. You can flip the switches as much as you...

The school inspection

A school teacher knew that the school superintendent would visit the next day. The superintendent would ask questions such as spellings or mental...

Missing petrol

During the gasoline transporting from one plant to another, the fuel tanker ever wasted 10 liters of gasoline. The process of filling the tank...