Question

The annual rate of growth in population of a certain city is 8%. If its present population is 196830, what it was 3 years ago?

Answer 1

Given details are,

Annual growth rate of population of city is = 8%

Present population of city is = 196830

Let population of city 3 years ago be = x

By using the formula,

A = P (1 + R/100)

196830 = x (1 + 8/100) (1 + 8/100) (1 + 8/100)

196830 = x (27/25) (27/25) (27/25)

196830 = x (1.08) (1.08) (1.08)

196830 = 1.259712x

x = 196830/1.259712

= 156250

∴ Population 3 years ago was 156250.