Hello guys I'm new here and I hope I'm asking this in the right place.

I'm sturting to study calculus by myself and I'm using apostol book.

Im still in the introduction part and I'm having some troubles by doing some proofs.

If x and y are arbitrary real numbers with x < y , prove that there is at least one real z satisfying x < z < y

The exercise is in the chapter of supremum and infimum, archimedean property of the real-number system

I appreciate any help