Ab,
Bb,
Db (C♯)
and Eb.
It depends on which key you are referring to, all the keys with flats are: F major (1 flat) B-flat major (2 flats) E-flat major (3 flats) A-flat major (4 flats) D-flat major (5 flats) G-flat major (6 flats) C-flat major (7 flats) Likewise the relative minors are: D minor (1 flat) G minor (2 flats) C minor (3 flats) F minor (4 flats) B-flat minor (5 flats) E-flat minor (6 flats) A-flat minor (7 flats)
There are three flats in the key signature of E flat major
Such a key only exists in theory. C major has zero flats. C-flat major has 7 flats. C-double-flat major would have 14 flats.
The key of A-flat major contains four flats: B, E, A, and D.
D flat major, or b flat minor. The flats are B, E, A, D and G, in that order.
Two flats, B flat and E flat
B flat Major has 2 flats and G Minor has 2 flats.
For c major there are no sharps, for b flat major there are two flats, b flat and e flat
The key of A flat major has four flats: B flat, E flat, A flat and D flat.
There are two flats in the key of B flat major: B flat and E flat.
The key of E-flat major has three flats, not sharps. The flats are B-flat, E-flat, and A-flat. In terms of sharps, it is the key that is a minor third above C major, which has no sharps or flats.
The key of B flat major, or g G minor, has two flats. The flats are B flat and E flat.