A memento is made as shown in the figure, its base PBCR is silver plated from the front side at the rate of ₹ 20 per cm 2 . Find the total cost of silver plating. (Takeπ 22 7 )

It is given that the radius of the quadrant is r = 7 cm and the front side of the base is been silver plated at the rate of ₹ 20 per

cm 2

We have to find the total cost of silver plating.
The area of a quadrant can be expressed as,

A = 14 π r 2

, where r is the radius of a circle.
The area of the region PBCR,

A s

is,

A s = area of △ ABC − area of quadrant ⇒ A s = 12 A B A C − 12 π r 2 ⇒ A s = 121010 − 14 π 72 ⇒ A s = 11.5 c m 2

So, the cost of the silver plating at the rate of rupees

20 / c m 2

is,

Cost = 11.5 \times 20

∴ Cost = ₹ 230

The total cost of silver plating is ₹230.
Therefore, the correct option is 4.

A memento is made as shown in the figure, its base PBCR is silver plated from the front side at the rate of ₹ 20 per $cm 2$ . Find the total cost of silver plating. $(Take π 227)$