Suppose in a pool of infinite items in a box, there are 30 item types we care about. The chance of pulling each item type that we care about is 0.0333%.
So we have Y1 ... Y30, with each has the same probability (0.0333%).
Is our chance of getting (Y1, Y2, Y3) the same as getting (Y1, Y1, Y2)? The order doesn't matter, so for our purpose, (Y1, Y2, Y3) is the same as (Y2, Y1, Y3) or (Y3, Y2, Y1).
What would be the approximate number of items we have to try before we can get (Y1, Y2, Y3), is that number the same as if we try for (Y1, Y1, Y2) or any other combinations?
Thanks!