The doctor told Anna that tomorrow she will have to check her blood pressure every 15 minutes from 1

The doctor told Anna that tomorrow she will have to check her blood pressure every 15 minutes from 10:00 AM to 4:00 PM. How many times does she have to take her blood pressure?

10:00 A.M. to 4:00 P.M. is 6 hours.

Each hour is 60 minutes

60 minutes divided by 15 minutes equals 4 blood pressure checks per hour.

4 blood pressure checks per hour * 6 hours = 24 blood pressure checks