It's asking me to find a^-5 From what I understood about inverses is that it's the element before you hit the identity would be the inverse. So a^5 = (a^5, a^10, a^15,..., a^90, a^95, a^100 = e), then a^-5 = a^95. The correct answer is actually a^20. Can anyone help me out with understanding inverses? Thanks!