A geometric serie is given by:
[tex]\sum_{k\mathop{=}0}^{\infty}a_1(r)^{k-1}[/tex]
Where:
a1 = First term of the sequence = 420
r= common ratio = 0.8
The srie sconverges if and only if:
[tex]\begin{gathered} -1he seris converge asnd its sum is gviven by:
[tex]\sum_{k\mathop{=}1}^{\infty}420(0.8)^{k-1}=\frac{a_1}{1-r}=\frac{420}{1-0.8}=2100[/tex]
