It is given that:
Length of a tile = 15m 17m = 1517cm [∵ 1m = 100cm]
Breadth of a tile = 9m 2m = 902cm
∴ Side of each square tile = HCF (1517, 902)
Prime factorization:
1517 = 37 × 41
902 = 22 × 41
∴ HCF = product of smallest power of each common prime factor in the numbers = 41
∴ Required number of tiles = Area of ceiling/Area of one tile = 1517 x 902/ 41 x 41 = 37 x 22 = 814
