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A gardener is asked to level a playground with the help of a roller 120 cm long and 50 cm in diameter. The roller takes 500 revolutions to level the playground. The gardener takes half a rupee per square meter. How much money has to be paid to the gardener?

Given, the length of a roller i.e., h = 120 cm

diameter of a roller = 50 cm

radius of a roller = 25 cm

The curved surface area of the roller = 2πrh

=2π (25) (120) cm² (we know that 1m = 100cm)

=2π (25) (120) × 10⁻⁴ m²

= 1.884 m²

∴ The area of the playground = The curved surface area of the roller x no. of revolutions

  = 1.884 × 500 = 942 m²

∴ The amount to be paid to the gardener = 942 × 0.5 = ₹ 471