A block of marble 5 m x 4 m x 2 m in size is cut into rectangular tiles of 1 m x 0.5m size having thickness of 10 cm. Assuming 10% wastage in cutting, how many tiles will be made?
First, we need to find the total volume of the marble block. The dimensions of the block are given as 5 m, 4 m, and 2 m.
The formula for the volume of a rectangular block (cuboid) is length × width × height.
So, the volume of the marble block ($V_{block}$) is: $V_{block} = 5 \, \text{m} \times 4 \, \text{m} \times 2 \, \text{m}$ $V_{block} = 40 \, \text{m}^3$
Next, we calculate the volume of a single rectangular tile. The dimensions are 1 m × 0.5 m with a thickness of 10 cm.
We must ensure all dimensions are in the same unit. Let's convert the thickness from centimeters to meters: $10 \, \text{cm} = \frac{10}{100} \, \text{m} = 0.1 \, \text{m}$
The volume of one tile ($V_{tile}$) is: $V_{tile} = 1 \, \text{m} \times 0.5 \, \text{m} \times 0.1 \, \text{m}$ $V_{tile} = 0.05 \, \text{m}^3$
The problem states that there is a 10% wastage in cutting. This means that only 90% of the total marble block volume is actually usable for making tiles.
To find the usable volume ($V_{usable}$), we calculate 90% of the total block volume: $V_{usable} = V_{block} \times (100\% - 10\%)$ $V_{usable} = 40 \, \text{m}^3 \times 90\%$ $V_{usable} = 40 \, \text{m}^3 \times \frac{90}{100}$ $V_{usable} = 40 \, \text{m}^3 \times 0.90$ $V_{usable} = 36 \, \text{m}^3$
Finally, to find the total number of tiles that can be made, we divide the usable volume of the marble by the volume of a single tile.
Number of tiles = $\frac{V_{usable}}{V_{tile}}$
Number of tiles = $\frac{36 \, \text{m}^3}{0.05 \, \text{m}^3}$
Number of tiles = $\frac{36}{0.05}$
To simplify the division, we can multiply the numerator and denominator by 100: Number of tiles = $\frac{36 \times 100}{0.05 \times 100} = \frac{3600}{5}$
Number of tiles = 720
Therefore, 720 tiles will be made from the block of marble, considering the 10% wastage.