Image source: http://www.cnn.com/HEALTH/9708/22/unstoppable.germ/bacteria.jpg
The exponent is often associated with time in exponential growth and decay
situations. For example, if bacteria in a culture doubles every hour, then the
number of bacteria, n, present after t hours can be represented
by the equation n = i2^{t}, where i is the initial amount of
bacteria present.
http://www.laxa.is/images/CarFacility.gif
If the value of an automobile decreases by 20% each year, then the price, p,
of a used car that is t years old can be determined by the equation p=n(0.80)^{t},
where n is the price of a new car.
