A rectangular box is twice as long as it is wide. If it were 3 inches shorter and 3 inches wider, it would be square. What is the width in inches of the box?

Let's denote the width of the rectangular box as "w" inches.
Given:
Length of the box is twice as long as its width: length = 2w inches.
If the box were 3 inches shorter and 3 inches wider, it would be square. This means the new length and width would be equal.
The new length would be (2w - 3) inches, and the new width would be (w + 3) inches.
Since the new length and width are equal, we can set up the equation:
2w - 3 = w + 3
Now, let's solve the equation to find the value of "w":
2w - 3 - w = 3
w - 3 = 3
w = 3 + 3
w = 6
Therefore, the width of the box is 6 inches.