2 A germ population has a growth curve of Aet At what value

2. A germ population has a growth curve of Aet At what value of i does its original value double? (A) 1.7 in (B) 4.7 (C) 7.7 (D) 97

original population= Ae^0.4t

let t=x for the population to be double= Ae^0.4x

NOW, relating two equations

2Ae^0.4t = Ae^0.4x

2 = (e^(0.4x-0.4t)

taking ln both side

ln2 = ln(e^(0.4x-0.4t)

0.693 = 0.4( x-t)

1.7325 = x-t

Hence for the population of bacteria to be double the value of t should be 1.73 more than original t.