The number, $N$, of people who have heard a rumor spread by mass media at time, $t$, is given by $$N(t) = a ( 1 - e^{-kt} ).$$ There are 200000 people in the population who hear the rumor eventually. 17 percent of them heard it on the first day. Find $a$ and $k$ , assuming $t$ is measured in days.
$a =$
$k =$