25 ; 5 ; 1 ; 0,2
b₁=25 b₂=5
q=b₂/b₁ = 5/25= 1/5
S∞ = b₁/(1-q) =25/(1-1/5) = 25:(4/5) = 25*(5/4 )= 125/4 =31,25
25 ; 5 ; 1 ; 0,2
b₁=25 b₂=5
q=b₂/b₁ = 5/25= 1/5
S∞ = b₁/(1-q) =25/(1-1/5) = 25:(4/5) = 25*(5/4 )= 125/4 =31,25
ответ: S∞ =31,25