Answer: 1
Step-by-step explanation:
The formula for calculating the sum of a Geometric series if the common ratio is greater than 1 is given as :
[tex]S_{n}[/tex] = [tex]\frac{a(r^{n}-1) }{r-1}[/tex]
Where [tex]S_{n}[/tex] is the sum of terms , a is the first term , r is the common ratio and n is the number of terms.
From the question:
[tex]S_{n}[/tex] = 3280
a = ?
r = 3
n = 8
Substituting this into the formula , we have
3280 = [tex]\frac{a(3^{8}-1) }{3-1}[/tex]
3280 = [tex]\frac{a(6561-1)}{2}[/tex]
Multiply through by 2 , we have
6560 = a ( 6560)
divide through by 6560, we have
6560/6560 = a(6560)/6560
Therefore : a = 1
The first term of the series is thus 1
