Substituting Values into Algebraic Expressions?

Gabby

New member
2. 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

The correct answer is D. 134. I don't get it. Can anyone plz explain why? Thanks in advance!
 
Back
Top