The students in a grade 10 class were investigating the algae growth rate on the surface of local lake. When they began, 425 cm^2 of the surface area of the lake was covered with algae. The amount of surface area covered with algae doubles each month. The students modelled this situation using the formula SA = 425(2)^n, where SA is the surface area of the lake covered in algae after n months. If conditions remain constant, how much of the lake will be covered in algae

a) after 6 months?

b) after 2 years?

7. A biologist is monitoring the population growth of caribou in a national park. There were 1400 caribou in 2010. The caribou population increases at a growth rate of 1.04% per year. The growth rate can be modelled using the formula P = 1400(1.04)^n , where P is the projected population after n years. Assuming that the growth rate remains constant, what would be the estimated caribou population in 2014? 8. A culture of bacteria in a lab contains 400 bacterium cells. The number of cells doubles every hour. This situation can be modelled by the equation B= 400(2)^h, where B is the estimated number of bacteria and h is the time in hours. How many bacteria were present

a) after 3 h?

b) after 24 hours?

c) 3 hours ago ?