The Frobenius Group F20 has 5 conjugacy classes.F = {a,b|a^5 - b^4 = 1, bab^-1 = a^2}.I think the conjugacy classes are [1],[a],[b],[b^2], and [b^3], but I'm having a hard time figuring out why [b^3] is a conjugacy class. I know, if a and b are cojugate, then |a| = |b|.|1| = 1, |a| = 5, |b| = 4, |b^2| = 2. So there are at least 4 conjugacy classes.But I'm not sure what to do now?