Question

a circular table top is to be polished . if diameter of the top is 70cm . find the cost of polishing it at the rate of Rs 250 m square.

Answer 1

$\boxed{\boxed{\mathbf{96.25}}}$

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Given:

Diameter = 70cm

Radius = $\mathsf{\frac{Diameter}{2} = \frac{70}{2} = 35cm}$

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To Find :

Cost of Polishing at rate of  $\mathsf{250 \: per \: m^2}$= ?

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Using the Formula,

$\large\mathbf{Area \: of \: Circle}$  = πr²

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Substituting the values in the Formula, we get,

$\textsf{Area of Circle}$ = $\mathsf{\frac{22}{7} \times 35 \times 35}$

$\mathsf{=> 22 \times 5 \times 35}$

=> $\boxed{\mathsf{3850 cm^2}}$

Converting it in $\mathbf{m^2}$,

Dividing it by $100 \times 100 = 10000$, we get

$\mathsf{\frac{3850}{10000}}$

=> $\large\mathbf{0.385 m^2}$

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Now,

Cost of Polishing 1m is $\mathsf{250 \: per \: m^2}$

=> $\mathsf{250 \times 0.385}$

=> $\boxed{\mathbf{96.25 \: Rupees}}$

Hence, the cost of Polishing the Circular top is $\mathsf{96.25 \: Rupees.}$