Question

Christina wants to compute the cost of tiling the floor in her bathroom. The floor measures 7 feet 6 inches by 8 feet 10 inches. Each tile covers 1 square foot. —A box of 45 tiles costs $35.95.

(Christina is buying 2 boxes)

What is the cost of the tile needed for this project?



I got an answer of $71.9. Is that correct?

Answer 1

Two boxes will cost
`\$35.95\cdot 2=\$71.9.` The cost of one tile is approximately
`(\$71.9)/(67)\approx \$1.08.`

Explanation:

Note that 1 ft = 12 in, then

`7\ ft\ 6\ in=7\cdot 12+6\ in =90\ in,\\ \\8\ ft\ 10\ in=8\cdot 12+10\ in=106\ in.`

The area of the floor is

`90\cdot 106=9540\ in^2.`

Now

`1\ ft^2=144\ in^2,`

then

144 sq. in - 1 tile,

9540 sq. in - x tiles.

Mathematically,

`(144)/(9540)=(1)/(x),\\ \\x=(9540)/(144)=66.25`

tiles is needed to cover the floor (67 full tiles).

Each box of tiles contains 45 tiles, so Cristina has to buy 2 boxes. These two boxes will cost
`\$35.95\cdot 2=\$71.9.` The cost of one tile is approximately
`(\$71.9)/(67)\approx \$1.08.`