Final answer:
To find the number of blue tiles on the floor, first calculate the total number of tiles by finding the floor area in cm² and dividing by the area of one tile. Then, use the given tile ratio to determine that there are 750 blue tiles on the floor.
Step-by-step explanation:
The question asks for the number of blue tiles on a floor where the ratio of blue to white tiles is 3:5, and the dimensions of each tile are 30cm by 30cm. The floor measures 15m by 12m. To find out the number of blue tiles, we need to calculate the total number of tiles first. Here are the steps:
Convert the floor dimensions from meters to centimeters as the tiles are measured in centimeters. Therefore, 15m = 1500cm and 12m = 1200cm.
Calculate the area of the floor in square centimeters, which is 1500cm × 1200cm = 1,800,000cm².
Find the area covered by each tile, which is 30cm × 30cm = 900cm².
Divide the total floor area by the area of one tile to find the total number of tiles: 1,800,000cm² ÷ 900cm² = 2000 tiles.
Now, use the ratio to find the number of blue tiles. The total ratio parts are 3+5=8 parts. Each part represents 2000 ÷ 8 = 250 tiles.
Since the ratio of blue tiles to white tiles is 3:5, there are 3 parts for blue tiles. So the number of blue tiles is 3 × 250 = 750 blue tiles.