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प्रश्न
The dimensions of a metallic cuboid are 100cm× 80 cm× 64cm. It is melted and recast into a cube. Find the surface area of the cube.
उत्तर
Let the edge of cube be a.
As,
Volume of cube = Volume of cuboid
`rArr a^3 = 100xx80xx64`
`rArr a^3 = 100xx80xx64`
`rArr a = root(3)(512000)`
⇒ a =80 cm
Now, the surface area of the cube = 6a2
=6 ×80 ×80
= 38400 cm2
So, the surface area of the cube is 38400 cm2.
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Solution :
The surface area of the sphere = 4πr2
= `4 xx 22/7 xx square^2`
= `4 xx 22/7 xx square`
= `square xx 7`
∴ The surface area of the sphere = `square` sq.cm.
