Probability question with combinations of different types of an item Suppose a bakery has 18 varieties of bread, one of which is blueberry bread. If a half dozen loafs of bread are selected at random (with repetitions allowed), then what is the probability that at least one of the loafs of blueberry bread will be included in the selection.
I started off by determining that if we picked up at least one blueberry bread from the start, then we could find the total ways by finding:
$C_{R}(n, r)$
Plugging in for $n$ and $r$ I calculated that the number of ways would be:
$C_{R}(18, 5) = C(18+5-1,5) = 26,344$ ways.
Am I on the right track, and how would I go about finding the probability in this case?

I don't think that's a very good direction. It could require much work. I always fond it useful to think of a simplified version: 
Suppose we pick 1 loaf. What are the chances of it being blueberry?
Suppose we pick 2 loaves. What are the chances of not having a blueberry?
3 loaves?
4 loaves?
