Some of you are so off it isn't even funny.
In each booster, there is five common cards, three uncommon cards, one rare card, and one reverse holo card. The reverse holo can be of any rarity, sans Level X cards or non-Shiny Secret Rares.
There are also three types of "super" rares. The first one are Pokemon Level Xs. In sets before Legends Awakened, you found 1 of these in about every 36 packs. Since Legends Awakened, you usually find Level Xs one in every 18 packs.
The second type of ultra rare cards are Shinies/Rotoms. You usually find one of these in every 18 packs, and these take up the RH slot in a pack.
The third type of ultra rare cards are Secret Rares. You usually find one of these cards in every 36 packs. Secret Rares are cards of which their set number is past the numbers of cards in the regular set. For instance, Charmander SF is 101/100, Electabuzz is 128/127, Surfing Pikachu is 114/111.
Hope this helps. =D