Exactly Mary. I went through an exercise myself on that one having read your post. It does seem to me that both yours and my thoughts can equally hold true, eg. to use this #10, if we looked at the tune in 2/4 we can say there are 2 beats of 1/4 note and the triplet is made of made of 1/8 notes so if we said there was a 2nd triplet starting at the expected 2nd beat and made of 1/8 notes, the 3 would make up one of the beat in the bar.
You are much better at maths that me but for what it's worth, I do agree with your Cakewalk "sums".