I know this is not to the usual caliber of your questions but I can't figure out this simple question:
A Cmaj is made out of $3$ notes, $C ,E ,G$. If those notes can appear in $9$ octaves, how many ways of making a Cmaj are there?
Bear in mind that you must select exactly 1 of each note in each appearance.
UPDATE: It is $9^3$ you can treat the problem as counting all possible $3$ bit base-$9$ numbers