AT SAME TIME inc at beg of 3rd & foll 6th rows, 5 times in all … 69 sts

Sorry that my first question on this forum is so long … I’m using a Patons “Easy to follow Pattern” from the 80s. My SLEEVE pattern is worked sideways and set into deep square armholes. I have 22 stitches on my needle after the first 2 rows,

then the pattern says:

Keeping patt correct and working extra sts into patt, cast on 3 sts at beg of alt rows 14 times, AT SAME TIME inc at beg of 3rd & foll 6th rows, 5 times in all … 69 sts.

I can’t get it to add to 69 sts!

First question is about the “alt rows” Do I cast on 3 sts at beg of THIS NEXT row and each other row until I’ve “cast on” a total of 42 extra stitches over the next 27 rows?

Second question is : Do I repeat 5 times the whole instruction: "inc on 3rd and 6th rows (i.e. INC 10 extra sts in total) or do I just inc 5 times - on 3rd, 6th, 3rd, 6th, and 3rd rows of pattern? this would add up to 69.

Huge thanks for your patience and help!
Jezza11

Cast on 3sts starting with the next row and then every other row after that until you have 42sts cast on or a total of 64sts. So you’re casting sts on in one row, skipping the next row, etc.
For the next direction, increase 5 times [I]total[/I]. That will give you the 69sts altogether.
Sounds like a fun pattern to do!