make up a set of twelve numbers that have the folling landmarks min 2 max 11 median 6 mode 6
O.K., this is a rather stupid question.
A possible tuple of numbers would be
(6;6;6;..;6), where there are 12 times this 6. However, this does not constitute a "set" concerning the rigorous mathematical definition of a set. Go and ask your math teacher to read a proper book on elementary set-based topology.