The answers to today’s problems

Earlier today I set you these three problems about the number 11. Here they are again with solutions.

1. Funny formation

You are the coach of a football team, whose players have shirt numbers 1 to 11. The goalkeeper wears 1. You must divide the others into defenders, midfielders and forwards.

You would like to arrange your team so that the sum of the shirt numbers in each group (defenders, midfielders, forwards) is divisible by 11?