How many different ways can a visiting nurse visit 6 patients if she visit them all in one day?

The visiting nurse can visit 6 patients in different orders, which can be calculated using the factorial of the number of patients. Therefore, the number of different ways she can visit the 6 patients is 6! (6 factorial), which equals 720. Thus, there are 720 different ways for the nurse to visit all 6 patients in one day.