Question

5. If Ms. Yamagata uses 18-inch tiles, what are the least number of tiles that she needs to buy to cover the floor? A. 30 B. 45 C. 68 D. 102

Answer 1

We will have the following:

*First: We determine the area:

`A=7.5\cdot9\Rightarrow A=67.5`

So, there is an area of 67.5 square feet, now we take that to square inches:

`\Rightarrow A=67.5\cdot144\Rightarrow A=9720`

So, there is an area of 9720 square inches in that bathroom.

*Second: We will determine the number of 18-inch tiles that can be accommodated in the length and width:

**Length: We take into account that for each foot there are 12 inches and that each tile has a side length of 8 inches, so:

`L=(9\cdot12)/(18)\Rightarrow L=6`

So, in the length, we can accommodate 6 18-inch tiles.

**Width:

`W=(7.5\cdot12)/(18)\Rightarrow W=5`

So, in the width, we can accommodate 5 18-inch tiles.

*Third: We determine the number of tiles we will need by multiplying the number of tiles that can be accommodated in the length times the tiles that can be accommodated on the width, that is:

`t=6\cdot5\Rightarrow t=30`

So, she will need 30 18-inch tiles.