Bb to D is a major 3rd.
The interval from B-flat to D is a major third, regardless of the key.
augmented 5th, as e flat to b flat is a perfect 5th and b is a semitone above b flat, making the interval augmented
E flat consists of 3 flats, B flat, E flat and A flat. E flat to B flat would be a perfect 5th interval as B flat is in E flat major, but because your question was E flat to B, B is a semitone up from B flat, this would mean the interval becomes a semitone larger, and a semitone larger from a perfect interval is augmented. Therefore, the answer to your question is an augmented 5th. Hope this helps :)
the interval is a 3rd.
B-flat to C-sharp is an augmented 2nd.
E-flat up to B-natural is an augmented 5th.
I think it would be a minor second. D flat to D double flat would be the equivalent of D flat to C.
B-flat up to G is a major 6th. Or, B-flat down to G is a minor 3rd.
Major first. (+1)
The interval from A to Bb is a minor 2nd, also called a half step.
It depends on what scale you're talking about. B flat major = B flat, C, D, E flat, F, G, A B flat harmonic minor (ascending and descending) = B-flat, C, D-flat, E-flat, F, G-flat, A (natural), B-flat, A (natural), G-flat, F, E-flat, D-flat, C, B-flat B flat melodic minor (ascending and descending) = B-flat, C, D-flat, E-flat, F, G (natural), A (natural), B-flat, B-flat, A-flat, G-flat, F, E-flat, D-flat, C, B-flat B flat natural minor = B-flat, C, D-flat, E-flat, F, G, A, B-flat
D flat F G B flat A flat F D flat B flat A flat A flat A flat then E flat G A C B flat G E flat C etc. Ending G G G G A flat D flat D flat D flat D flat