Krystian works in the library. He borrows an average of 40 books every day. Every Friday, his number of borrowed books is about 40% higher than the daily average. How many books does he borrow in a week if the library is open from Monday to Friday? Let's answer step by step:
The number of books borrowed on Friday is higher by 40 * 40 / 100 = 16 books. There are 5 days from Monday to Friday inclusive, so Krystian borrows an average of 5 * 40 = 200 books during that time. With Friday's increase in borrowings, during one week Krystian borrows 200 + 16 = 216 books. The answer: 216.