What is the number of 15-centimetre square tiles required to cover a rectangular floor 5.4 m long and 4.05 m wide?
The area of the floor can be had by mutiplying length * width, so
1) Area = length * width
2) Area (floor) = 5.4 m * 4.05 m
3) Area (floor) = 21.87 m^2
The area of a given tile is, again determined by length * width; assuming it's 15 cm on a side, the area would be 15 cm multiplied by itself. But we've already got the floor area in defined in meters ^2, so let's convert. Since there's 100 centimeters in 1 meter, 15 centimeters = .15 meters. So the area of the tile is
4) Area (tile) = .15 m * .15 m = .0225 m^2
To figure the number of tiles, divide. Note that the units (m^2) cancel, leaving an integer:
5) 21.87 m ^2 / .0225 m ^2 = 972 tiles
The rectangular floor has length 5.4 m = 540 cm and width 4.05 m = 405 cm.
It has to be covered with square tiles of length 15 cm.
540 divided by 15 is equal to 36 which is a whole number. If the tiles are laid on the floor it will have 36 rows. 405 divided by 15 is equal to 27, this again is a whole number and can be taken to be the number of columns formed when the tiles are laid on the floor. Using this, the total number of tiles required to cover the floor is 36*27 = 972.