Sooty Tern In $1979,$ there were 12 million sooty terns (a bird) in the world. Assume that the percentage of terns that survive from year to year has stayed constant at $83 \%$ and that approximately 2.04 million terns hatch each year. (Source: Bryan Nelson, Seabirds: Their Biology and Ecology, New York: Hamlyn Publishing Group, 1979 )
a. How many of the terns that were alive in 1979 are still alive?
b. Write a function for the number of terns that hatched $t$ years after 1979 and are still alive.
c. Estimate the present population of sooty terns.