Doctors use the term maximum heart rate (MHR) when referring to the quantity found by
starting with 220 beats per minute and subtracting 1 beat per minute for each year of a
person’s age. Doctors recommend exercising 3 or 4 times each week for at least 20 minutes
with your heart rate increased from its resting heart rate (RHR) to its training heart rate
(THR), where THR = RHR + .65(MHR – RHR)
Which of the following is closest to the THR of a 43-year-old person whose RHR is 54 beats
per minute?
A. 197
B. 169
C. 162
D. 134
E. 80
