Tentukan banyak siku barisan geometri berikut 100,20,4,...,4/125

jawab

a = 100
r = 1/5

a r^n-1 = 4/125
100,  (1/5)^(n-1) =  4/125
(1/5)^(n-1) = 4/12500= 1/3125= (1/5)^5
n-1 = 5
n = 6
banyak suku = 6