and no boxes were removed, all the boxes in the warehouse were arranged in stacks of 14 boxes each, with no boxes left over. How many boxes were in the warehouse before the 60 additional boxes arrived

360 boxes

Step-by-step explanation:

The number of boxes in the warehouse before 60 boxes were added is;

n = 12k  equation 1

where k is the constant of the number of stacks and n is the number of boxes.

The number of boxes after the 60 boxes were added is;

n + 60 = 14k ... equation 2

substitute the value of n in equation 2 for equation 1:

12k + 60 = 14k

60 = 14k - 12k

60 = 2k

k = 60 / 2 = 30

The number of boxes in the warehouse before 60 boxes was added is;

n = 12 * 30 = 360