Question:
Mark (✓) against the correct answer:
The annual rate of growth in population of a town is 5%. If its present population is 4000, what will be its population after 2 years?
(a) 4441
(b) 4400
(c) 4410
(d) 4800
Solution:
(c) 4410
Present population =4000
Rate of growth = 5%
To find the population of the town after 2 years, we have:
$A=P \times\left(1+\frac{R}{100}\right)^{n}$
$=4000 \times\left(1+\frac{5}{100}\right)^{2}$
$=4000 \times\left(\frac{105}{100}\right)^{2}$
$=4000 \times\left(\frac{21}{20}\right) \times\left(\frac{21}{20}\right)$
$=(10 \times 21 \times 21)$
$=4410$