I have a test in music theory tomorow and I do not understand how to figure out the quality of an interval. For example, for Triads and Seventh chords. I know that if there is a Major third stacked on a major third then the triad is Augented. If there is a minor 3rd stacked on a Major third then it is a Perfect 5th and vice versa. If there is a minor third stacked on top of a minor then it is diminished. But how the heck do I figure out if the interval is Major or minor?