5. Tick the correct answer:
(c) Normal range of breathing rate per minute in an average adult person at rest is:
(i) 9–12
(ii) 15–18
(iii) 21–24
(iv) 30–33
Normal range of breathing rate per minute in an average adult person at rest is (ii) 15–18
This means on an average, an adult human being breathes in and out 15–18 times in a minute.