Answer:
1162.94 km²
Step-by-step explanation:
forest cover area = 3900 km²
Area decreases every year by = 7.75 %
area after 15 years(A) = ?
[tex]A=P(1-\dfrac{r}{100})^{15}\\A =3900(1-\dfrac{7.75}{100})^{15}\\A = 1162.94 / km^2[/tex]
so, the area of forest remaining after 15 years as it decreases by 7.75 % every year is equal to 1162.94 km²