Idiom of the day :- How on earth…? How in the world…?

Usage, examples and definition of the Idiom :-

When asking a question, “How on earth…” and “How in the world…” emphasize the fact that something incredible or very hard to believe happened. ex. “How on earth did you get that job? (it was very hard to get)”; “How on earth did you fix that car!? (it was impossible to fix)”.