a) Given,

Heart beats 75 times a minute

Converting minute into seconds, we get,

1 min = 60 s

As, frequency (f) is the number of times the heart beats in a second

Therefore, we get,

f = 75\over 60 = 1.25 Hz

Hence, **Frequency = 1.25 Hz**

(b) Time Period (t) = 1\over f

Substituting the values, we get,

t = 1\over 1.25 = 0.8

Hence, **t = 0.8 s**