Question

Use this Ms. Yamagata is going to tile the floor of her rectangular bathroom that is 9 feet long and 7. feet wide. The cost per 6-inch tile is $0.50. The cost per 18-inch tile is $2.75. 4. If Ms. Yamagata uses 6-inch tiles, what are the least number of tiles that she needs to buy to cover the floor?​

Answer 1

252 6-inch tiles can cover the floor completely.

Explanation:

For a rectangle of length L and width W, the area is:

A = L*W

In this case we know that the floor is 9ft long and 7 ft wide, then:

L = 9ft

W = 7ft

Because the tiles are in inches instead of ft, I will rewrite those measures on inches.

Here we need to use:

1ft = 12 in

Then:

L = 9ft = 9*( 12in) = 108 in

W = 7ft = 7ft*(12in) = 84 in

Then the area of the floor is:

A = 108in*84in = 9,072 in^2

In this case, Ms. Yamagata wants to only use 6-inch tiles to cover all the floor.

The area of a 6-inch tile is:

a = (6 in)*(6 in) = 36 in^2

The total number of 6-inch tiles that she needs to use, is the quotient between the area of the whole floor, and the area of one tile, this is:

N = A/a = (9,072 in^2)/(36 in^2) = 252

She needs to use exactly 252 tiles to cover the floor.