Fill the square on the left with red, yellow, green, and blue chips so that no row, no column and neither of the two long…

One of the greatest unsolved problems in mathematics was whether any map needed more than 4 colours assuming that no regions which shared an edge…

Katrina and her class are on a camping trip. Today, everyone gets a single potato for supper. It’s not much, but at least they should…

There are only two laws in Circle Town. Nobody can walk outside. This means that children must learn to drive from a very young age.No…

Game for 1-4 players. Rules:If one of the roles was a “1” the player scores zero points, otherwise the player scores the sum of his…

The people of Utopia had divided into two political parties. The “Bread & Butter” party offered daily bread & butter to all the people. The…

“Tài Wù, oh great ancestor, tell us – will the first day of the week will be unlucky?” Gu took the red hot poker and…

The crafty British pirate, Blackbeard (Spaniards called him Barbanegra), had a keen mind for mathematics. The following are excerpts from a diary found in a…

How many of you are there?How many parents do you have?How many grandparents?How many great grandparents?How many great great grandparents?How many great great great grandparents?How…

Bob the Building has only one elevator, so as people leave for work (going from floors 1-6 to the ground floor) or come home from…