Okay, here we have this;
Considering the provided information, we are going to calculate the requested widths, so we obtain the following:
Let us remember that the volume of a box is equal to the multiplication of its three dimensions, so from the given information we obtain the following:
Kyle's box Volume=Long * High * Width
12 ft^3=2ft * 3ft * Width
12 ft^3=6 ft^2 * Width
Kyle's box Width =12 ft^3/6 ft^2
Kyle's box Width = 2 ft
Myla’s box Volume=Long * High * Width
16 ft^3=4ft * 2ft * Width
16 ft^3=8 ft^2 * Width
Myla’s box Width =16 ft^3/8 ft^2
Myla’s box Width = 2 ft
Finally we obtain that the widths of Kyle and Myla’s boxes are 2 ft.