A) The population of a country has grown at a rate proportional to the number of people in this country. At present, the country has 75 million inhabitants. Six years ago, it had 63 million. Assuming...

Extracted text: A) The population of a country has grown at a rate proportional to the number of people in this country. At present, the country has 75 million inhabitants. Six years ago, it had 63 million. Assuming that this trend continues, find: (a) an expression for the approximate number of people living in the country at any time t (taking t = 0 to be the present time). (b) the approximate number of people who will inhabit the country at the end of the next fifteen-years period.