There are 20 alligators in the swamp. Each year, the number of alligators increases by 25%. There are 25 crocodiles in the swamp. Each year, 10 new crocodiles join the swamp.
Part B: How many alligators are in the swamp after 4 years? How many crocodiles are in the swamp after the same number of years?
Part C: After approximately how many years is the number of alligators and crocodiles the same? Justify your answer mathematically.