What is the minimum number of identical square tiles required to tile a floor of length 6 m 24 cm and width 4 m 80 cm ?

Answer: Option B

Length of largest tile = H.C.F. of 624 and 480 cm = 48 cm
Area of each tile = (48 × 48) cm²
∴ Required number of tiles :
$$\begin{array}{rl}& =\left(\frac{624\times 480}{48\times 48}\right)\\ & =130\end{array}$$