Question

the poulation of a certain special decays over time according to equation
y=A(0.39)^(t/50) .Where A = the population of the species present intially and t = time in years , If the intial population was 500,000 after how many years would 5,000 remain?

Answer 1

Didn't I just answer this one?
Set y = 5000, and A = 500 000

Answer 2

I did but not match answer

Answer 3

how u solve?