Question

The diameter of roller 120 cm long is 84cm.if it takes 500 complete revolutions to level a playground,determine the cost of levelling it at the rate of 30 paise per square metre.

Answer 1

Answer:

Cost for leveling the ground is Rs. 475.20.

Step-by-step explanation:

Diameter = 84cm

Therefore,

Radius (r) = 42cm

Height (h) = 120cm

Area rolled in 1 revolution = Curved surface area

= 2 × 22/7 × r × h

= 2 × 22/7 × 42 × 120

= 31680 cm² = 3.168 m^2

Therefore,

Area covered by roller in 500 revolutions = 31680 × 500

= 15840000 cm²

= 1584 m²

Therefore,

$Cost \: for \: levelling = Rate × Area \\ \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: = 30 \: paise × 1584 \: m^{2} \\ \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: = \frac{30}{100} \times 1584 \\ \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: = Rs. \: \: 475.20</p><p>$

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