If the Inspiratory Capacity (IC) of a person’s lungs is approximately 3,000 mL, his Expiratory Reserve Volume (Reserve) is 1,100 mL, what would be the Vital Capacity of his lungs? 

Vital capacity (VC) is the maximum amount of air a person can expel from the lungs after a maximum inhalation. It is the sum of inspiratory capacity (IC) and expiratory reserve volume (ERV). 
IC = 3,000 mL
ERV = 1,100 mL
VC = IC + ERV 
VC = 3,000 mL + 1,100 mL
VC = 4,100 mL