Answer:
Explanation:
Exhaled air for 90 minutes would be 40 breaths per minute (at 1 litre per breath) x 90 minutes =3600 litres x 0.16= 576 litres of oxygen, In other words, first work out the amount of air breathed out in litres/minute and then multipy by the number of minutes to get the total litres of air breathed out and then multiply that figure by 0.16 (16 % oxygen per volume of air) to get total litres of oxygen breathed out
