Employers shall provide a studio teacher on each call for minors from age fifteen (15) days to their sixteenth (16th) birthday (age sixteen (16)), and for minors from age sixteen (16) to age eighteen (18) when required for the education of the minor. One (1) studio teacher must be provided for each group of ten (10) minors or fraction thereof. With respect to minors age fifteen (15) days to age sixteen (16), one (1) studio teacher must be provided for each group of twenty (20) minors or fraction thereof on Saturdays, Sundays, holidays, or during school vacation periods.