Question

a road roller is 140 cm long and its diameter is 84 CM it takes 1000 Revolution to move over to level the road find the cost of levelling at ₹50/ square metre

Answer 1

Answer:

Given,

Length (h)  = 140 cm

diameter (d) = 84 cm

radius  (r) = d/2

r = 84/2 = 42 cm

Area covered in one complete revolution =surface area of raod = 2×$\pi$× r× h

=> 2 ×$\frac{22}{7}$ × 42 × 140 $cm^{2}$

= 12x 22 x 140  $cm^{2}$

=36960  $cm^{2}$

covered area in 1000 revolution   10000× surface area of road roller

= 36960 x $10^{3}$ $cm^{3}$

=3696 $m^{2}$

now,

Cost = surface area of roller × Rate

=> 3696 x 50/100

=> 1848 Rs

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@GauravSaxena01

Answer 2

given,
Length(h)=140cm
diameter (d)=84cm
radius(r)=d/2
r=84/2=42cm
Area covered in one complete revolution=surface area of road=2×π ×r×h
=2×22×42×140cm2
___
7
=12×22×140cm2
=36960cm2