Hey guys, I'm new here, but already have a question

Basically, the task at hand is as follows. You have a set of 52 cards, out of which you randomly draw 8. What's the probability of an event that either a) three aces will be drawn

**or **b) three kings will be drawn

**or **c) three aces and three kings will be drawn.

This is from a high school textbook and the solution says the said events are going to happen in (4 3)(48 5) + (4 3)(48 5)

**+ **(4 3)(4 3)(44 2). I get the first two, but I don't get why there is a plus in front of the third. Shouldn't there be a minus? I mean, the event c) is already covered in both the events a) and b), so if anything you should subtract that event so that it isn't counted twice. If my thinking isn't correct, what am I missing?

Thanks in advance, everyone, I've been doing this problem for hours, but still can't figure out where I'm going wrong. Oh, and sorry for not using Latex, I'm not familiar with it. Those (4 3) etc. are supposed to represent binomial symbols, with 4 being "n" (at the top) and 3 being "r" (on the bottom).