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

45 markers in each box.

Step-by-step explanation:
Initially, the school had 3 boxes of board markers, and each box had X board markers, where X is the number we want to find.
Then the initial number of board markers is 3*X.
We know that after giving 15 markers to 3 teachers, we have other 90 markers left. This can be written as:
total markers = markers for the teachers + markers left
3*X = 15*3 + 90 = 45 + 90 = 135
now, we divide both sides by 3.
X = 135/3 = 45
From this, we know that in each box we have 45 markers

1. 0.3 •4 is the same as 4 groups of 0.32. 7•0.8 is the same as 7 groups of 0.83. it increases by 0.5 every time, so 0.5x4 it increases by 0.9 every time, so 0.9x5. 0.9•12=10.86. 0.47•5=2.35i can finish the next ones in a separate post