Population after 5 years = 534
Solution:
Given population, P = 690
Rate decrease, R = 5%
Number of years, n = 5
If the population decrease constantly R% , then the population after n years is
[tex]P(1-\frac{R}{100} )^n[/tex]
Substitute the given values in the above formula.
[tex]P(1-\frac{R}{100} )^n=690(1-\frac{5}{100})^5[/tex]
Cross multiply 1 and 100 to get the same denominator.
[tex]=690(\frac{100-5}{100})^5[/tex]
[tex]=690(\frac{95}{100})^5[/tex]
[tex]=690(\frac{19}{20})^5[/tex]
= 533.90
= 534
Hence the population after 5 years is 534.
