What possibilities are there for the number of solutions of a linear congruence (mod 20)?
Hello,
check this out, it will tell you how to find the number of solutions & the solutions of any linear congruence
Linear congruence theorem - Wikipedia, the free encyclopedia
The wiki article is not that shiny, so if this is not enough, google "Linear Congruence Theorem"
Thank you; I had this theorem in my mind, but wasn't sure if that was what the question was asking. I take it that the number of solutions for a linear congruence (mod 20), then, would be d, where d=gcd(a,20) in the set of residues {0, 1, ..., 19}? Thanks so much for your help!