Who's older Batman or superman

Answer 1

Superman's first appearance was in "Action Comics #1," cover dated June 1938. Batman's first appearance was in "Detective Comics #27," cover dated May 1939. Thus, in the real world, Superman is older. If, on the other hand, you are referring to characters, there is no clear answer to that which I am aware of. They are treated in the comics as contemporaries of similar age, and those ages aren't specified exactly. (Superhero ages rarely are these days, to better facilitate the "fluid" timelines that happen because the characters don't age nearly as rapidly as their readers.)