SOLUTION: A minor chord is composed of notes whose frequencies are in the ratio 10:12:15. If the first note of a minor chord is A with a frequency of 220 hertz, what are the frequencies of t

The record  A:B:C = 10:12:15 means, by definition, that there is a quantity x such that A = 10x, B = 12x, C = 15x,

and this quantity "x" is called  "a common measure".


So, in our case, that means that the common measure is 220 Hz = 10x; hence, x =  = 22 Hz.


Then other two notes are 12*22 = 264 Hz  and  15*22 = 330 Hz.