Three cubes of edge 3cm, 4cm, 5cm are melted to form a single cube . find the lateral surface area of the new cube ?

by turvi

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Three cubes of edge 3cm, 4cm, 5cm are melted to form a single cube . find the lateral surface area of the new cube ?

by turvi

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= a³+b³+c³

= 3³+4³+5³

= 27+64+125

= 216cm³

Edge of a new cube = ∛216 = 6cm

Lateral surface area of a cube = 4a² = 4*6*6 = 144cm²

volume of 2nd cube=4 x 4 x 4=64

volume of 3rd cube =5 x 5 x 5=125

therefore volume of new cube =27+64+125=216

a³ =216

a=6

therefore lateral surface area of cube =4a²=4 x 36

=144 m² ans