The probability of anything is the number of ways that something can happen that you consider to be a success, in this case drawing either a face or a black card, out of the total number of ways that it can happen at all. A deck has 52 cards so that is the denominator. There are two red suits and two black suits, so half of the cards are black. Then there are 3 face cards in each of 4 suits making 12 in all -- but half of those are black and have already been counted. So the numerator of your probability fraction is the number of black cards plus the number of red face cards.
My calculator said it, I believe it, that settles it