The diameters of the top and the bottom portions of a bucket are `42 cm` and `28 cm.` If the height of the bucket is `24 cm,` then find the cost of painting its outer surface at the rate of `5 (paise) /(cm^2)`.

Explanation

bucket top radius `r_{1}=frac{42}{2}=21 cm`

bucket bottom radius ` r_{2}=frac{28}{2}=14 cm`

bucket height ,` h=24 cm`.



`l=sqrt{h^{2}(r_{1}-r_{2})} `


`=sqrt{576+(21-14)^{2}} `


`=sqrt{576+49} `


`=sqrt{625} `


`=25`



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