Answer:
0.155
Step-by-step explanation:
nth term of a geometric sequence = ar^n-1
Where,
a = first term
r = common ratio
n = number of terms
Given:
100, 80, 64,...
a = 100
r= 80/100
= 4/5
30th term of a geometric sequence = ar^30-1
= ar^29
= 100 × (4/5)^29
= 100 × (0.8)^29
= 100 × 0.00155
= 0.155
Therefore,
30th term of the geometric progression = 0.155
