To calculate the maximum heart rate in beats per minute (bpm) for a person, use the expression 220−a , where a is the person's age in years. what is the maximum heart rate for the given ages? enter your answers in the boxes. if a person is 20 years old, their maximum heart rate is bpm. if a person is 31 years old, their maximum heart rate is bpm. if a person is 48 years old, their maximum heart rate is bpm.