What is the sum of this geometric series?5 + 25 + 125 + 625 + 3,125 + 15,625?

The explicit formula for the sum of the geometric series is:

Sn=[a (rⁿ-1) ] / (r-1)

where:

a=first term

n=number of terms

r=common ratio

From the series given:

5 + 25 + 125 + 625 + 3,125 + 15,625?

a=5

r=5

n=6

thus the sum of the series will be:

Sn=[5 (5 ⁶-1) ] / (5-1)

Sn = (5 (15625-1)) / 4

Sn=78120/4

Sn=19530

Answer: 19530