## No five countries can all boarder each other

Looking on the world map you can easily spot four countries that border each other. But can you find five?

## Some ideas on teaching graph theory in high schools

Have you ever wondered how you can make mathematics interesting to the daily life of students? In this article, we will discuss two important and exciting concepts teachers can use to introduce graph theory in their classes.

## Playing with Colors Part 2: An open problem related to graph colouring

Mathematicians often enjoy playing around with the concept of infinity and in the following, I will describe a problem defined on an infinite graph!

## Playing with Colors

Part 1: Learn about applied and theoretical aspects of graph coloring: a tool that helps us design exam schedules or even solve Sudoku!

## How many colors do you need to color a map?

A mathematician once told me that problems that are very simple to state can be very deceiving, and sometimes turn out to be extremely difficult to solve. One such problem was the Four Color Problem.

## A solution to a long standing conjecture

Recently a team of mathematicians has published an article announcing a solution to a long standing open problem in graph theory, the Erdős - Faber - Lovász (EFL) conjecture. This conjecture was formulated in 1972 by mathematicians Paul Erdős, Vance Faber and László Lovász.