tech
February 2, 2026
Did you solve it? The numbers all go to 11
Earlier today I set you these three problems about the number 11. Here they are again with solutions.
TL;DR
- It is impossible to divide a football team's outfield players (numbered 2-11) into three groups (defenders, midfielders, forwards) where the sum of shirt numbers in each group is divisible by 11.
- There are nine additional palindromic results when multiplying numbers from 11 to 99 by 11, beyond the initial set of palindromes (11x1 to 11x9).
- The largest 10-digit number using digits 0-9 exactly once that is divisible by 11 is 9876524130.
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