Question 12
The central bank of Sikinien mints coins worth $11$ and $12$ Kulotnik. In a burglary, eleven Sikinien thieves broke into a safe and stole coins with total value $5940$ Kulotnik. They tried for a while to divide the loot fairly, so that everyone received the same value, but could not do so. After a while their leader claimed to have reasoned that this was indeed impossible. Prove that they did not steal any coin worth $12$ Kulotnik.