Answer:
Sn = 315
The sum of the first six terms of the series is 315
Completed question:
Find the sum of the first six terms of the geometric series in which a1=160, a6= 5 and r= ½
Explanation:
The sum of a geometric series in with common ratio
r < 1 is;
Sn = a(1 - r^n)/(1-r)
Where;
r = common ratio
a = first term
n = nth term
Given;
r = 1/2
a = a1 = 160
n = 6
Substituting the values, we have;
Sn = 160(1 - (1/2)^6)/(1 - 1/2)
Sn = 315
The sum of the first six terms of the series is 315