Question

Population of a town increases at the rate of 5% per year. In the year 2012 population of the town was 1,20,000. So in the year 2015, population will be = ? (3) 138951 (4) 139918 (2) 139915 (1) 138915​

Answer 1

Answer:

138915

Step-by-step explanation:

We will use the formulae for compound interest here.

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

here,

A will be the population after 3 years (2012 - 2015)

P will be the population in 2012

R = 5

n = 3

$A = 120000(1 + \frac{5}{100} )^{3}$

$A = 120000(1 + \frac{1}{20} )^{3}$

$A = 120000(\frac{21}{20} )^{3}$

$A = 120000 * \frac{21}{20} * \frac{21}{20} * \frac{21}{20}$

$A = 15 * 21 * 21 * 21$

$A = 138915$