Question

The population of a city is 1,20,000 if the population decreases by 5% every year, what will be the population after 3 years ?

• A. 103,885
• B. 102,875
• C. 102,885
• D. 102,880

Answer 1

The correct option is C 102,885

Given

P= Present population of city= 1,20,000

R= -5 p.c.p.a ( since it is decreasing)

A = Population after three year

$=P(1+\frac{r}{100}{)}^n$

$=1,20,000(1+\frac{-5}{100}{)}^3$

$=1,20,000(\frac{95}{100}{)}^3$

$=1,20,000\times \frac{95}{100}\times \frac{95}{100}\times \frac{95}{100}$

$=1,02,885$

The population after three years = 1,02,885