I think that equation is supposed to look like this:
[tex]A(t)=50(.8) ^{t} [/tex]
The reason I say that is because this is an exponential decay problem, with a starting amount of 50 pieces of candy.
If that's the case, then it would look like this with a t value of 5:
[tex]A(5)=50(.8) ^{5} [/tex]
and [tex]A(5)=50(.32768)[/tex]
so the amount of candy left after 5 minutes is 16.384 or 16
