3. The number N of bacteria present in a culture at time t, in hours, obeys the law exponential growth N(t) = 500e^0.02t a) How many bacteria are there at t = 0 hours? b) When will the number of bacteria triple? Solution put t=0 N(0)= 500e0= 500 bacteria triple N(t) = 500*3 = 1500 1500=500e0.02t 3=e0.02t ln3=0.02t t = ln3*50 =50ln3.