Question

Dave tiled his bedroom floor which is 80 sq.ft. He had 4 rows of tiles with 10 tiles in each row. How many tiles did Dave use to tile a floor of 100 sq.ft? Solve using unit rate.

Answer 1

To determine how many tiles Dave would need to tile a floor of 100 sq. ft., we can first find out how many tiles he used for the 80 sq. ft. floor and then use that information to calculate the number of tiles needed for 100 sq. ft.

1. **Calculating the total number of tiles used for 80 sq. ft.:**
Dave has 4 rows of tiles, with 10 tiles in each row. Therefore, the total number of tiles is:

\[
\text{Total tiles} = \text{Number of rows} \times \text{Tiles per row} = 4 \times 10 = 40 \text{ tiles}
\]

2. **Finding the unit rate of tiles per square foot:**
To find the number of tiles per square foot, we divide the total number of tiles by the area of the floor they cover:

\[
\text{Unit rate (tiles per sq. ft.)} = \frac{\text{Total tiles}}{\text{Area}} = \frac{40 \text{ tiles}}{80 \text{ sq. ft.}} = 0.5 \text{ tiles per sq. ft.}
\]

3. **Calculating the number of tiles needed for 100 sq. ft.:**
Now that we know there are 0.5 tiles needed per square foot, we can find the number of tiles needed for 100 sq. ft.:

\[
\text{Tiles needed} = \text{Unit rate} \times \text{Area} = 0.5 \text{ tiles per sq. ft.} \times 100 \text{ sq. ft.} = 50 \text{ tiles}
\]

Therefore, Dave would need **50 tiles** to tile a floor of 100 sq. ft.