Four!
In a standard deck of 52 playing cards, there are two black 8s: the 8 of spades and the 8 of clubs. Each suit contains one card of each rank, and since there are two black suits (spades and clubs), there are two black 8s in total.
There are 50 8s in 400
There are 70 8s in 560
39 of them.
3