Answer:
The answer is 25%
Explanation:
on the first year lets say town A and town B had a population of 100 (a town wouldn't have only 100 people but for simplicity lets do 100).
town A's population increases by 60%, 60% of 100 is 60, 100 + 60 = 160
town B's population decreases by 60%, 100 - 60 = 40
so now we have town A's population after 10 years and town B's population after 10 years, 160 divided by 40 = 4, and 100 divided by 4 equals 25, so the answer is 25%.