Answer:
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Formula: 1 Mark
Application: 1Mark
Steps: 1 Mark
Answer: 1 Mark
Given that,
Population 2 years ago =62500.
Rate of decrease = 4 % p.a.
For population 1 year ago,
P = 62500 , R = 4 %, T = 1 year
$\therefore S.I=\frac{P\times R\times T}{100}$
$\Rightarrow I=\frac{62500\times 4\times 1}{100}$
$\Rightarrow I=2500$
$\Rightarrow$ After 1 year the population will decrease by 2500 people
$\therefore$ Population 1 year ago is = 62500 - 2500 = 60,000
For present population,
P = 60,000, R = 4 %, T = 1 year
$\therefore S.I=\frac{P\times R\times T}{100}$
$\Rightarrow I=\frac{60000\times 4\times 1}{100}$
$\Rightarrow I=2400$
$\Rightarrow$ Present population = 60,000 - 2400 = 57,600
[We are subtractingthe population because population is decreasing by 4% p.a.]
The present population is 57,600.