Q2 of 24 Page 164

Two cubes, each of volume 512 cm3 are joined end to end. Find the lateral and total surface areas of the resulting cuboid.

Given, Two cubes of volume 512 cm3each and they are joined end-to-end.


The side of each cube=?


We know, Volume of a cube = (side)3.


So, Volume = (side)3


512 = (side)3


Side = 8 cm


We know, Lateral Surface Area of cuboid = 2h(l+b)


Lateral Surface Area = 2h(l+b)


= 2×8×(16+8)


= 16×24


= 384 cm2


We know, Surface area of a cuboid= 2 × (lb + bh+ hl).


Total surface areas of the resulting cuboid= 2 × (lb + bh+ hl)


= 2×(16×8 + 8×8 + 8×16)


= 2×( 128 + 64 + 128 )


= 2× 300


=600 cm2


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