Odds Per Pack refers to the chances that a particular pack will contain a specified card. Each pack operates as its own independent event, so your chances or "odds" are on a per-pack basis.
This means if a pack has a 1:10 chance at a collectible, you will have the same 1:10 chance at acquiring the collectible in the first pack as you do on the tenth.

Looking for additional information on how independent odds work?
Check out the video HERE!