Your "granny gear" is worn, but as noted above, it should be fine with a new chain, it's not too bad yet. The other two look better.

And second the admonition to clean the drivetrain more often. Regular cleanings could easily double your drivetrain life (chain/cassette, rings don't wear as fast). Also, google the chain measurement method referenced above. Replace your chain before it is way whacked out, it'll save a lot of headaches.