Which of the following are examples of exponential decay?
- The population of a Florida is increasing by 43% each year.
- The pesticide DDT has a half-life of 15 years.
- March Madness has 64 teams in the bracket. Each round, half the teams are eliminated.
- After an antibiotic is added to a culture of bacteria, the number of bacteria is reduced by half every three hours.
- A tree frog population doubles every three weeks.