Initially there is about 500 ml of air in our lungs. During normal breathing about 12% of the air in the lungs get replaced after one breath.
a) Write an exponential model to represent the amount of original air left in the
lungs.
b) Use the model to find out how much of the original air is present in the lungs after
25 breaths?
Note: the original air left in the long decrease with each breath.