Perform the following calculations: (show all work in a logical progression to the final answer)
a. A city has a population of 50,000 in 2012. If the population of the city grows at an annual rate of 2
b. A country's population was 12 million in 1992 and in 2012 it is 24 million. If the population grew at a constant rate, What percent rate of growth was it?