I am trying to solve a variation on the coupon collector's problem.
In this scenario, someone is selecting coupons at random with replacement from n different possible coupons. However, the person is not selecting coupons one at a time, but instead, in batches.
Here's an example problem formulation: There are 100 distinct coupons. A person makes selections in 10-coupon batches at random (each coupon with replacement). What is the expected number of batches necessary to have selected 80 unique coupons?
I have been able to determine the expected number of selections necessary to have selected k unique coupons when selecting one at a time (much like Henry's answer to a similar question), but I'm a bit stumped as to how to go about solving it with this particular wrinkle.
Any tips/guidance would be greatly appreciated.