Discrete Structure 3.2

20. A certain protected species normally doubles its population each month. The initial population is 20, but by the beginning of the next month, 1 specimen has died of an infection. In successive months, the infection kills 2, then 4, then 8, and so forth. a. Write a recurrence relation for the size of the population at the beginning of month n. b. Solve this recurrence relation c. What is the size of the population at the beginning of month 7