Answer:
170 heart beat per minute.
Step-by-step explanation:
While exercising, a person’s recommended target heart rate is a function of age. The recommended number of beats per minute, y, is given by the function y = f(x) = − 0.85x + 187 where x represents a person’s age in years.
So, if my age is 21 years i.e. x = 21, then the number of recommended heart beats per minute for my age will be
y = f(21) = - 0.85(21) + 187 = - 17.85 + 187 = 169.15 ≈ 170. (Answer)
{Taking the larger integer value}