Justine earned $30,000 during the first year of her job at city hall. After each year she received a 6% raise. Find her total earnings during the first five years on the job.

Answer 1

This is a geometric series with
a = 30000
r = 1.06

so you want:
30000 + 30000(1.06) + 30000(1.06)^2 + ... + 30000(1.06)^4
= 30000(1.06^5 - 1)/(1.06 - 1)
= 169112.79