Answer:
372
Step-by-step explanation:
We are given that the dimensions of the box are,
Length = 15 cm, Width = 20 cm and Height = 9 cm.
We know that the box represents a cuboid.
Since, surface area of a cuboid = L×W + 2×L×H + 2×W×H
Thus, the surface area of the box = 15×20 + 2×15×9 + 2×20×9
i.e. Surface area = 300 + 270 + 360
i.e. Surface area = 930.
Thus, the surface area of the box is 930 cm² i.e. 9300 mm².
Further, the sides of the tiles are 5 mm and the tile represents a square.
So, the surface area of the tile = 5 × 5 = 25 mm².
This gives us that,
Number of tiles required to cover the box = = 372.
Hence, Dmitri requires 372 tiles to cover the box.