A school ordered 3 large boxes if board markers. After giving 15 markers to each of 3 teachers, there were 90 markers left. How many markers were originally in each box

45 markers were in each box.

Step-by-step 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.