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Question
In Fig. 5, from a cuboidal solid metallic block, of dimensions 15cm ✕ 10cm ✕ 5cm, a cylindrical hole of diameter 7 cm is drilled out. Find the surface area of the remaining block [Use
`pi=22/7`]
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Solution
Surface area of the remaining block = Surface area of the cuboid + Curved surface area of cylinder − 2 × Area of base of cylinder
`=2(15xx10xx+10xx5+15xx5)+(2xx22/7xx7/2xx5)-(2xx22/7xx7/2xx7/2)`
= 583 cm2
Thus, the surface area of the remaining block is 583 cm2.
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