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

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465.30 Rs

425.20 Rs

475.20 Rs

300.10 Rs

answer is C.

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Detailed Solution

Concept- Because there are travel expenses per square meter. Therefore, calculate the area to find the total cost for leveling the playground. As a cylindrical roller, it covers the area corresponding to the curved surface with one rotation. The formula for the curved surface (S) of a cylinder is:

Given, diameter of cylinder is 120cm
Height of the cylinder is 84 cm
Surface area of cylinder is:

; Radius(r)=

30 paise is the cost of traveling per square meter
The area covered by the roller is 500 revolution is

3168 cm to m is

Cost for 500 revolution is

Converting paise to a rupee

Rs
Hence, the correct answer is option 3) 475.20 Rs.

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