Find the sum of the first 8 terms of the geometric series 1+5+25+125
The given series is a geometric series with a common ratio of 5.
The formula to find the sum of the first n terms of a geometric series is:
S_n = a * (1 - r^n) / (1 - r), where a is the first term and r is the common ratio.
In this case, a = 1 and r = 5.
So, S_8 = 1 * (1 - 5^8) / (1 - 5)
S_8 = 1 * (1 - 390625) / -4
S_8 = 1 * (-390624) / -4
S_8 = -390624 / -4
S_8 = 97656
Therefore, the sum of the first 8 terms of the given geometric series is 97656.