Lines 1-2 say, "Mayhem may be short on charm, But he is
an overachiever." What literary device is Salinger using
here, and how do you know?

well if u read the book you would know that she meant to

i'm thinking it would be when compound subjects are joined by or, nor,either-or, neither-nor.

you need to write a question based on a prompt. you have not given the prompt, and therefore this question cannot be answered on unless you provide it.

the anwser is our hope this