Answer:
4.225 L
Explanation:
The box has a height of 21 cm. After the box is filled to 18 cm, there's 3 cm left of space. The volume of this space is:
V = lwh
V = (25 cm) (37 cm) (3 cm)
V = 2775 cm³
1 cm³ is the same as 1 mL, so the volume of the space is 2775 mL.
1 L is 1000 mL, so this volume is 2.775 L.
7 L of water is then poured in. The box can hold 2.775 L. The rest overflows. The overflow volume is:
7 L - 2.775 L = 4.225 L