The population of a city increases by 5% per year but due to migration it decrease by 1% per years. What will be the percentage increase in population in 3 years? Pick: A) 9 % B) 9.27 % C) 27 % D) 12.48 % E) none of these

Rationale: "actual increase in population = 4 % let , earlier population = 100 then the population after 3 years = 100 ( 1 + 4 / 100 ) ^ 3 = 112.4864 ∴ required percentage = 12.48 % answer : d"
Answer: D