Answer:
3 highlighters and 5 permanent markers were sold on Monday.
Explanation:
Since the school store sells highlighters for $ 1.20 and permanent markers for $ 1.15, there is a difference between the two products of 5 cents, or $ 0.05.
Therefore, if 8 products were sold for a total of $ 9.35, and since 1.15 x 8 equals 9.20, there is a difference of 15 cents, attributable to the highlighters, since each highlighter costs 5 cents more than the permanent markers .
Therefore, since 15/5 is equal to 3, on Monday 3 highlighters and 5 permanent markers were sold, which is corroborated by the following calculation:
3 x 1.20 = 3.60
5 x 1.15 = 5.75
5.75 + 3.60 = 9.35