Lemma
DeepCounting
#15 · Combinatorics · Counting

Two subsets, one sum

Given any ten distinct two-digit numbers (from 10 to 99), prove that two different subsets have the same sum.

~25 minWritten answer · compare with the solutionPigeonholeCounting subsetsBounding sums
Stuck? A gentle nudge
Something off?
Workspace
Your working

Check your full solution

Upload photos of your handwritten work or a PDF, and Lemma will read it and tell you whether it's right — and where it first goes wrong if not.