- Apr 19, 2022
- 5 min
The Seven Bridges of Königsberg
The city of Königsberg, now Kaliningrad, is located on the two shores of the Pregel River. In the early 1700s seven bridges connected two...
Prove that from a set of ten distinct two-digit numbers (in the decimal system), it is possible to select two disjoint subsets whose members have the same sum.
A fun beginner's exercise in using the pigeonhole principle to solve Olympiad-style problems!