My first proof employing the pigeonhole principle / dirichlet's box principle - very simple theorem on real numbers. Please mark/grade.
What do you think about my first proof employing the pigeonhole principle? What mark/grade would you give me? Besides, I am curious about whether you like the style. Theorem Among three elements ...
Let n be a positive integer. Show that in any set of n consecutive integers there is exactly one divisible by n. Here is the solution: Let $a,~a+1,...,a+n-1$ be the integers in the sequence. ...