4. To tile a floor, they used 150 square tiles with 40cm side length. What is the area of the floor...

To convert the area to square meters, we divide by 10,000 (since 1 square meter is equal to 10,000 square centimeters). Therefore, the area of the floor is 240,000 / 10,000 = 24 square meters.

Since there are 150 square tiles used to tile the floor, the total area covered by the tiles is 150 x 1600 = 240,000 square centimeters.

Each square tile has a side length of 40cm, so the area of each tile is 40cm x 40cm = 1600 square centimeters.