A trading card series has 200 different cards in it, which are sold in 5-card packages.

Each package has a random sampling of the cards (assume that any card of the 200 has an equal chance of being in a package).

On the average, how many packages will need to be bought to collect the complete series if...

A: all the cards in a package will always be different

B: a package can have repeats

The minimum number of packs is 40 (200/5) [very unlikely]

The maximum number of packs required is infinite [extremely unlikely]

with 80 packs, it is very likely that there will be several triples, and possibly some quadruples, etc. Enough to keep you from completing the set.

The answer is very likely around 100 packs, but I don't know where.

Because 5 is small compared to 200, and there would be so many extras already, I suspect that case B will yeild pretty much the same answer as case A

Posted by TomM on 2002-05-10 08:32:37