You can
put this solution on YOUR website!"The population P of a certain culture is expected tp be given by a model P=100e^rt where r is a constant to be determined and t is a number of days since the original population of 100 was established. I need to find the value of r if the population is expected to reach 200 in 3 days."
P=200
t=3

Take the natural log of both sides

remember: ln(a^m)=mln(a)

remember: ln(e)=1

Round off to whatever you are asked for.
Happy Calculating!!!