A typical cup of coffee contains about 100 mg of caffeine and every hour approximately 13% is metabolized and eliminated.

(a) Write $C$, the amount of caffeine in the body in mg as a function of $t$, the number of hours since the coffee was consumed.
$C(t) =$ mg help (formulas)

(b) How much caffeine is in the body after 3 hours? mg (Round your answer to three decimal places.)