Two solid cubes each of volume 8,000 cm³ are joined end to end. Find the cost of painting the resulting cuboid all around at the rate of ₹25 per 100 cm².
₹1,000
Each cube has a volume of 8,000 cm³, so the side length of each cube is ∛8000 = 20 cm. After joining the cubes, the cuboid has dimensions 20 × 20 × 40 cm. The surface area of the cuboid is:
Surface Area = 2 × (20 × 20 + 20 × 40 + 20 × 40) = 2 × (400 + 800 + 800) = 4000 cm²
The cost of painting = (4000/100) × 25 = ₹1,000.
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