I'm stuck on one part of a problem.

"suppose where t is odd, and for odd prime p and positive integer e.

Let L be the subgroup of false witnesses, i.e. L is the set of congruence classes made up of integers b prime to n such that

Now suppose the order of L is .

Let g be a primitive root mod n,so g has order and every element prime to n is of the form for some j.

Show that for every integer belonging to a congruence class in L, j must be even. Since |L|=t, explain why "

I really don't know what to do here so any help would be appreciated.