Anybody out there that knows how to find the number of possible outcomes or probability of a situation?

I know it deals with factorials, but I can't remember how you do it. For instance, in this lotto game I play called Mega Millions, you pick 5 numbers from 1 to 56 and you pick one number from 1 to 45 as your Mega Ball number to go with the other five numbers. Well, there is a way that you can figure out the total number of possible outcomes (There are a million and change numbers of outcomes, I do know) by using factorials in a formula. I need help in figuring it out because I want to use that factorial formula for another situation to figure the number of outcomes. Can anybody show me using the Mega Million example I gave in this paragraph?