The heart rate and the stroke volume of a person at rest are 70 beats per minute and 70 mL/beat respectively. During jogging, his heart rate increases to 90 beats per minute and stroke volume increases to 100 mL/beat. During jogging, his cardiac output increased by

Cardiac output = stroke volume x heart rateHis cardiac output at rest = 70 mL/beat x 70 beats/minute =  4,900 mL/minuteHis cardiac output during jogging = 90 mL/beat x 100 beats/minute =  9,000 mL/minuteDifference = 9,000 mL/minute - 4,900 mL/minute = 4,100 mL/minute = 4.1 litre/minute