The first thing you should do is calculate how much is the percentage of growth per hour. For this, we make the following rule of three: 12 ---> 100% 18 ---> x We clear x: x = (18/12) * (100) x = 150% Therefore, the population increases by 50% every hour. We now look for the function that models this problem: y = A (b) ^ x Where: y = total population A = initial population b = exchange rate x: time (in hours, in this case) Substituting values: y = 12 * (1.5) ^ x Let's check for 2 hours (x = 2): y = 12 * (1.5) ^ 2 y = 27 Which is correct Answer: The function that models the problem is: y = 12 * (1.5) ^ x
