Question

The present population of a town is 25000. It grows at 4%, 5% and 8% during first year, second year and third year respectively. Find its population after 3 years.

Answer 1

Here,
P = Initial population = 25, 000
\[ R_1 = 4 % \]
\[ R_2 = 5 % \]
\[ R_3 = 8 % \]
n = Number of years = 3
∴ Population after three years = P \[\left( 1 + \frac{R_1}{100} \right)\left( 1 + \frac{R_2}{100} \right)\left( 1 + \frac{R_3}{100} \right)\]
\[ = 25, 000\left( 1 + \frac{4}{100} \right)\left( 1 + \frac{5}{100} \right)\left( 1 + \frac{8}{100} \right)\]
\[ = 25, 000\left( 1 . 04 \right)\left( 1 . 05 \right)\left( 1 . 08 \right)\]
 = 29, 484
Hence, the population after three years will be 29, 484.