Question

The population of a city 2 years ago was 125000. Due to migration to cities the population decreases every year at 4% per annum. What is its present population​

Answer 1

Answer:

Solution:-

Present population=125000

Time=2 years (n=2)

Rate of depreciation=4%

$An=P( {1 - \frac{r}{100} )}^{2}$

$= 125000( {1 - \frac{4}{100} )}^{2}$

$= 125000 {(1 - \frac{1}{25} })^{2}$

$= 125000( { \frac{(25 - 1)}{25}) }^{2}$

$= 125000 \times \frac{24}{25} \times \frac{24}{25}$

= 200×24×24

= 115200

Hence,

Present population=115200