According to United Nations, the population of the world at the start of 2020 was about 7.795 billion, and it is growing at about 1.05% per year. a. Again, according to the model, how long will it take the population to double? Solve this algebraically; that is, do not simply use a table or graph. b. In what year will the population reach 20 billion? Again, solve without resorting to a table of values or a graph