The rate of change of the male population of a particular barangay is proportional to the male population at any time. If the present male population of the barangay is 30,000 and then years ago, there were 20,000 males in the barangay, when will the population double its present count? How many males were there 4 years ago?

Regression

Growth of Bacteria The growth rate of Escherichia coli, a common bacterium found in the human intestine, is proportional to its size. Under ideal laboratory conditions, when this bacterium is grown in a nutrient broth medium, the number of cells in a culture doubles approximately every 20 min.