Square tile has perimeter of 1.2m.
Square tile has four equal sides which form the perimeter.
Thus, length of each side of square tile
= 1.2m / 4
= 0.3m
Number of tiles lying on each side of the floor
= 4.8m / 0.3m
= 16 tiles
Total number of tiles
= 16 * 16
= 256 tiles
Cost of covering floor
= Rs 27 * 256
= Rs 6912