Answer:
Volume = 18 cubic feet
Surface Area = 44 square feet
Double width = Double the space
Explanation:
Please see attached explanations.
Surface area is the area (one side multiplied by another) of every side of the storage box, added together.
I have labeled each unique pair of sides as a, b, and c. That is top and bottom, left and right side, and front and back side.
Volume is the length multiplied by the width multiplied by the height.
By doubling the width, you are doubling the size of the box in that given direction. You can prove this mathematically by making the width twice of what it was and finding volume again.