A historical reference, along with a solution and interesting links for the Konigsberg bridge problem is found at this site: https:
https://www.scientificamerican.com/article/how-the-seven-bridges-of-koenigsberg-spawned-new-math/
This site provides a nice discussion of minimum spanning trees.
http://www.people.vcu.edu/~gasmerom/MAT131/mst.html
This is a nice interactive demonstration of Krukal’s algorithm:
http://students.ceid.upatras.gr/~papagel/project/kruskal.htm
Problem 45 presents “The Oracle of Bacon.” You will have fun with this site playing this trivia game.
http://oracleofbacon.org/