A hall 50 m long and 45 m broad is to be paved with square tiles. Find the largest tile as well as its number in the given options so that the tiles exactly fit in the hall :

Answer: Option C

Length of hall = 50 m
Breadth of hall = 45 m
Area of hall = (50 × 45) m
Maximum length of a square tiles = HCF of 50 m and 45 m = 5 metres
Area of tiles = 5 × 5 = 25 sq. m
∴ Number of tiles :
$$\begin{array}{rl}& =\frac{50\times 45}{25}\\ & =90\text{ tiles}\end{array}$$