Final answer:
Barbara will use a total of 30 square tiles to cover her craft room floor, where 18 tiles are red, comprising 6/10 of the total.
Step-by-step explanation:
The student is asking about tiling a floor and wishes to know how many square tiles are needed in total if 6/10 of the tiles are red and she has used 18 red tiles.
To solve this, we use a proportion where 6/10 (the proportion of red tiles) is equivalent to 18 (the number of red tiles) over the total number of tiles (x).
Create an equation from the proportion:
\(\frac{6}{10} = \frac{18}{x}\)
Solve for x by cross-multiplying:
\(6 \cdot x = 18 \cdot 10\)
\(6x = 180\)
\(x = \frac{180}{6}\)
\(x = 30\)
So, Barbara will use a total of 30 square tiles to cover her craft room floor.