Okay so maybe it's not impossible, but neither I nor any of my other classmates were able to figure it out.

if on any given day it snows, there is a .3 probability that it will snow the following day. if on any given day it doesn't snow, there is a .8 probability that it will not snow the following day. what is the probability that it will snow on any given day?

It was a question on our final, and I simply guessed (it was multiple choice). Anyone have any ideas?