Each mon will have its own 10% chance. If I did the math correctly, the chance to get at least one item after a battle is about 47%. --- https://www.youtube.com/user/17Master Official Milotic of the Omega Ruby and Alpha Sapphire boards.
Having 6 pokemon with a 10% chance will yield 6 independent 10% chances to get an item. This means you'll have a 90% chance of not getting and item.
For you to get no items, you'd have to have all 6 yield none, so that'd be (0.9x0.9x0.9x0.9x0.9x0.9), which is 53%. So you'd have a 47% chance of finding an item. --- 3DS FC: 1134-8061-2200; SV 3273; IGN: Dano; List: http://tinyurl.com/meg2s5l Beartic, Piloswine, and Snorunt - My Friend Safari is Ice because I'm so cool.