Friendship relationships between 6 people are represented by the following graph in which each person occupies a circle.
In addition, we know that:
- Alan has 3 friends: Barney, Charlie, and Daniel.
- Barney and Ed are both friends of Charlie.
- Ed is Frank's only friend.
What is the position of each person on the chart?
Seen at wild.maths.org.
This is the solution: