"Analysts work in a variety of fields to break down complex problems and find solutions. When interviewing candidates, employers are looking for applicants who have strong analytical and problem-solving skills as well as an in-depth knowledge of the field. For more information on the specific questions you'll be asked, try researching a particular role such as business analyst, financial analyst, programming analyst, or data analyst."
How many gas stations are in the US?
No idea how to answer that question without sounding like a fool.
These types of problems are meant to challenge your problem solving and critical thinking ability. We tell all candidates at the start of the problem: "It's not about getting the right answer. What's more important is how you work through the problem and, using what you know, come up with the best estimate." We hope that more than anything you will welcome the challenge and be eager to tackle it using your genius! :-)