Q.12 How many tiles whose length and breadth are 12 cm and 5 cm, respectively will be needed to fit in a rectangular region whose length and breadth are respectively?
(a) 100 cm and 144 cm
(b) 70 cm and 36 cm

(a) Area of rectangle = 100 × 144
= 14400 cm
Area of one tile = 5 × 12
\(= 60 cm^2 \)
Number of tiles = \(\frac{(Area of rectangle)}{(Area of one tile)} \)
\(= \frac{14400}{60} \) = 240
Hence, 240 tiles are needed
(b) Area of rectangle = 70 × 36
\(= 2520 cm^2 \)
Area of one tile = 5 × 12
\(= 60 cm^2 \)
Number of tiles = \(\frac{(Area of rectangle)}{(Area of one tile)} \)
=\(\frac{2520}{60} = 42 \)