(a) Total area of the region = 100 × 144 = 14400 cm2
Area of one tile = 12 × 5 = 60 cm2
Number of tiles required = 14400/60 = 240
Therefore, 240 tiles are required.
(b) Total area of the region = 70 × 36 = 2520 cm2
Area of one tile = 60 cm2
Number of tiles required = 2520/60 = 42