Answer: 0.81
or 0.36

Explanation:
Let length of the given cuboid = l
Therefore, according to the question,width of the cuboid = l/2
Now, the height of the cuboid = 0.5
Again according to the question,
The area of the base is 1.08m² less than the combined area of the sides.
Therefore, 2(l+l/2) ×0.5 - l×l/2 = 1.08
⇒

⇒

⇒

⇒ l = 1.2 m or 1.8 m
Thus, width of the cuboid = 0.6 m or 0.9 m
⇒ Therefore, the volume of the box, V = 1.2 × 0.6 × 0.5 or 1.8 × 0.9 × 0.5
⇒ V = 0.36
or 0.81