Question 6878
Let's get everything in meters. A tile is .25 meters on a side.
How many tiles would it take to make one strip of tiles 5 meters long?
Hint: it takes 4 tiles to cover a meter. To cover 5 meters would take ....?
Let's call the number of tiles used in a strip "x."
Next, how many stips of 5 meters do we have to cover the floor? However many there are, the total number of tiles used is 240. The total number of tiles in each strip with length 5 meters is x. We have 240/x strips!
Now, how wide is each strip? .25 meters because they are square tiles.
So if we divide the number of strips we have that are .25 meters wide by 4, we have calculated how many strips we have that are a meter wide. And that's how wide the floor is!

Numerically,
5 / .25 = 20
240/20 = 12
12 / 4 = 3

If you follow all this you would say the floor is 5 x 3 meters.