Diagonals of each (shape / rhombus) tiles
d1 = 45cm, d2 = 30cm
Total tiles = 3000
Total area = 3000 × Area of each tile = 3000 × 1/2 × d1 × d2
= 3000 x 1/2 × 45 × 30 = 2025000 cm2
= \(\frac {2025000}{100\times 100}\) m2 = 202.5m2
∴ Cost of polishing the floor at the rate of Rs. 2.50 per a square metre 202.5 × 2.50
= Rs. 506.25