Question

the inner diameter of a circular well is 3.5 metre it is 10 metre deep calculate its inner curved surface area the cost of plastering the cover surface area @ 40 per metre square
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Answer 1

Answer:

⇢ Inner curved surface area = 109.9 m²

⇢ Cost of plastering = Rs.4396

$\rule{100}{2}$

Given:-

• Inner diameter of well(d)= 3.5m
• Depth of well (h) = 10 m
• Rate of plastering = @Rs.40 per m²

To find:-

• Inner curved surface area = ?
• Cost of plastering = ?

At first,

$\twoheadrightarrow\sf{Radius = \dfrac{Diameter}{2}}\\\\\twoheadrightarrow\sf{Radius = \dfrac{3.5}{2}}\\\\\twoheadrightarrow\sf\red{Radius = 1.75 \: m}$

As we all know,

$\star\:{\boxed{\mathfrak\green{Curved\: surface \: area = 2\pi rh}}}$

• Plugging values:-

$\twoheadrightarrow\sf{Curved \: surface \: area = 2 \times 3.14\times 1.75 \times 10}\\\\\twoheadrightarrow\sf{Curved \: surface \: area = 6.28 \times 17.5}\\\\\twoheadrightarrow\large{\underline{\boxed{\sf\blue{Curved \: surface \: area = 109.9 \,m^2}}}}$

$\therefore{\underline{\bold{Inner \:Curved\:surface \: area = 109.9\,m^2}}}$

$\rule{200}{1}$

Now,

$\dashrightarrow\sf{Cost \: of \: plastering = Rate \times CSA}\\\\\dashrightarrow\sf{Cost \: of \: plastering = 40 \times 109.9}\\\\\dashrightarrow\large{\underline{\boxed{\sf\green{Cost \: of \: plastering = Rs.4396}}}}$

$\therefore{\underline{\bold{Cost \: of \: plastering = Rs.4396}}}$

Answer 2

Answer:

Step-by-step explanation:

Solution :-

Radius = 3.5/2 m

Height = 10 m

Inner curved surface area of the well

= 2πrh

= 2 × 22/ 7 × 3.5/2 × 10m²

= 22 × 5 m²

= 110 m²

Cost of plastering 1 m² = Rs 40

= Cost of plastering × curved surface area of the well

= Rs 110 × 40

= Rs 4400

Thus, Inner curved surface area of the well is 110 m² and Cost of plastering is Rs 4400.