AUC41  A rare piece of porcelain is assumed to appreciate at the rate of 3 + 0.2t measured in thousands of dollars per year when t is measured in years.  If this stamp is purchased for a newborn child and allowed to appreciate, what will be the value of the stamp on the child's 18th birthday?

Solution:  This is a growth (rate) problem requiring an integral.  The stamp is purchased for $3000.  Integrate the rate over time with the limits of 0 and 18 to find the value after 18 years.

In 18 years the stamp will be worth $86,400.