57. The changes in a city’s population from one decade to the next decade for 3 consecutive decades were a 20% increase, a 30% increase, and a 20% decrease. About what percent was the increase in the city’s population over the 3 decades?

Answer and Explanation

Your Answer is

Correct Answer is C

Explanation

Assuming the initial population is x, the population after 30 years: x(1+20%)(1+30%)(1-20%)=1.248x, the total growth rate is: (1.248-1)× 100% ≈ 25%