# A roller 140 cm long has a radius of 35cm.to level the playground it takes 980 complete revolutions. Determine the cost of levelingthe playground at the rate of 75paisaper square metre

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by minswsu9ripa

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by minswsu9ripa

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height, h = 140 cm = 1.4 m

radius, r = 35 cm = 0.35 m

The roller takes 980 revolutions to level the playground.

Thus, Area covered by roller = Area of playground.

∴Area of playground = 980 * Curved Surface Area of Roller

= 980 * 2πrh

= 980 * 2 * 22/7 * 0.35 * 1.4

= 21128.8 / 7

= 3018.4 m²

Thus, area of the playground is 3018.4 m²

3018.4 m² (?)

= 3018.4 * 0.75

= Rs. 2263.8

Thus, the cost of levelling the playground should be Rs 2263.8

= 2 × 22/7 × 35 × 140

= 30800 sq.cm

surface area of the play ground = 980 ×30800

= 30184000 sq.cm

= 3018.4 sq.m

cost of leveling the play ground = 75 × 3018.4 paise

= 226380 paise

= 2263.8 rupees