Question

The population of a certain city was 72000 on the last day of the year 1998. During next year it increased by 7% but due to an epidemic it decreased by 10% in the following year. What was its population at the end of the year 2000?

Answer 1

Given details are,

Population of city on last day of year 1998 = 72000

Increasing rate (R) in 1999 = 7%

Decreasing rate (R) in 2000 = 10 %

By using the formula,

A = P (1 + R/100)

x = 72000 (1 + 7/100) (1 – 10/100)

= 72000 (107/100) (90/100)

= 72000 (1.07) (0.9)

= 69336

∴ Population at the end of the year 2000 will be 69336.