Entry-Level Job- Background Check?

<p>How much do employers delve into your background during a background check for entry-level jobs. Specifically into your employment history? Like if you had part-time jobs/internships will they look into the specific number of hours you worked each week? The reason I ask this during an interview I was asked how many hours a week I worked in each job I had. I gave values that now I remember are a couple hours off. Like I said 10 hours/week but it was more like 7-10 hours/week depending on the workload of that week. I should have said it varied during the interview but it slipped my mind. Is this grounds for rescinding my offer?</p>