Answer:
45 markers were in each box.
Explanation:
To solve the problem, the total number of markers must be calculated and then divided by the number of original large boxes.
The number of markers is calculated as follows:
90 left over, 15 for each teacher and there are three teachers, that is, 15 * 3 = 45
That is: 90 + 45 = 135 markers in total.
Therefore per box would be 135/3 = 45 markers were in each box.