Question

Find the sum of the first 7 terms of the following series, to the nearest integer.

Answer 1

Answer:

$r = 2.5 \\ sum = \frac{a( {r}^{n - 1} )}{r - 1} \\ = \frac{125( {2.5}^{7 - 1} )}{7 - 1} \\ = \frac{30517.6}{6} \\ = 5086.3$