Step-by-step explanation:
The dolphin species decreasing rate per year = 3.1 %
The number of dolphins present currently = 20,000
The number of dolphins available after 30 years = ??
By population depreciation formula,
[tex]Pn = P (1 - R/100)^{T}[/tex]
where Pn is the population after 30 years,
P is the current population
R is the decreasing rate per year
T is the time after n years, in this case 30
[tex]Pn = P (1 - R/100)^{T}[/tex]
= [tex]20000(1 - 3.1/100) ^ {30}[/tex]
= 7775.76 = 7776.
