Abuilder needs to tile a 7 foot by 8 foot room with one-foot square tiles. how many tiles will she need?

  56 tiles.

Step-by-step explanation:

Given : A builder needs to tile a 7 foot by 8 foot room with one-foot square tiles.

i.e. Area of a tile = 1 square foot.

Now, the area of the room is given by :-

Now, the number of tiles required is given by :-

Hence, she will need 56 tiles.