a bucket made up of metal sheet is in the form of a frustum of a cone of height 16 cm with radii of its lower and upper ends as 8 cm and 20 cm respectively. find the cost of the bucket if the cost of the metal sheet is Rs. 15 per 100 cm^{3 }( use pi= 22/7)

Height of the bucket, *h* = 16 cm (Given)

Let the radii of the upper and lower ends of the bucket be *r*_{1} and *r*_{2 }respectively.

Given, *r*_{1} = 20 cm and *r*_{2} = 8 cm.

Surface are of bucket

= Curved surface area of the bucket + Area of base of the bucket

= π(*r*_{1} + *r*_{2})*l* + π*r*_{2}^{2 }

= π [ (*r*_{1} + *r*_{2})*l *+ *r*_{2}^{2} ]

= [ (20 cm + 8 cm) 20 cm + (20 cm)^{2} ]

= (28 × 20 cm^{2} + 400 cm^{2})

= ( 560 cm^{2} + 400 cm^{2} )

= × 960 cm^{2}

= 3017. 14 cm^{2 }(Approx)

Given, cost of 100 cm^{2} metal sheet = Rs 15

(Approx)

Thus, the cost of the bucket is approximately Rs 452.60.

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