Five With Zero Sum
What is the smallest $N$ such that among any $N$ integers (not necessarily distinct) there are always five whose sum is divisible by 5? Give an integer.
Related problems & prerequisites
Worth solving first
- Differences of Squares 5.0/10
- Hidden Progressions 5.0/10
- Guaranteed Pair Sum 4.0/10
Source: The Erdős-Ginzburg-Ziv theorem (1961), case n = 5. Statement written for AxiomIQ.