My guess would be 1:1000 chance of that. Hope I’m wrong though.

I hope you're wrong too. Hopefully at least one box will have 10 different.

Although that fact only reduces the odds by about 2.5 of randomly inserted, so:

10 diff Random

1:1 1:2.6 chance of getting 10 different in 1 box

1:31.8 1:83.1 chance of getting 20 different in 2 boxes

1:28.4K 1:74.4K chance of getting 30 different in 3 boxes

1:4.1 billion 1:10.1 billion chance of getting 40 different in 4 boxes

1:1.1E+20 1:2.9E+20 chance of getting 50 different in 5 boxes

It sounds depressing when you look at that.

Patrick, do you have any "space related" odds for 1:2.9E+20. Like trying to see the Christmas decorations on my house from the moon with the unaided eye?