Except for one face of given cube, identical cubes are glued through t

1.	Except for one face of given cube, identical cubes are glued through their faces to all the other faces of the given cube. If each side of the given cube measures 3 cm, then what is the total surface area of the solid thus formed ? (a) 225 cm2 (b) 234 cm2 (c) 270 cm2 (d) 279 cm2
Answer» (b) 234 cm² When one cube is pasted on each of 5 faces of a cube, then Surface area of each cube pasted = 5x² = 5 × (3)² cm² = 45 cm² For 5 faces, total area = 5 × 45 cm² = 225 cm² But surface area of the bottom face where the cube is not pasted = x² = 32 = 9 cm² ∴ Total area = 225 cm² + 9 cm² = 234 cm².

Except for one face of given cube, identical cubes are glued through their faces to all the other faces of the given cube. If each side of the given cube measures 3 cm, then what is the total surface area of the solid thus formed ? (a) 225 cm2 (b) 234 cm2 (c) 270 cm2 (d) 279 cm2

Answer»

(b) 234 cm²

When one cube is pasted on each of 5 faces of a cube, then

Surface area of each cube pasted = 5x²

= 5 × (3)² cm² = 45 cm²

For 5 faces, total area = 5 × 45 cm² = 225 cm²

But surface area of the bottom face where the cube is not pasted = x² = 32 = 9 cm²

∴ Total area = 225 cm² + 9 cm² = 234 cm².