Answer:
97,655
Step-by-step explanation:
5(5)^(n-1) = 78,125
5^n = 78,125
n = 7
=> S7 = 5(5^7 -1) / (5-1)
= 5/4 (78, 125 -1)
= 5/4 (78 124) = 97,655
