Two cubes each of side 4 cm are joined end to end to form a cuboid. Find the volume of the resulting cuboid.

Class 8MensurationMensuration

Step-by-Step Solution

Each cube has volume

4^{3} = 64 cm^{3}

. Joining two cubes gives total volume

64 + 64 = 128 cm^{3}

Answer: D) 128

A cuboid has 3 pairs of identical opposite faces. Their total area:

- 2 faces of

l \times b

(top + bottom)
- 2 faces of

b \times h

(front + back)
- 2 faces of

l \times h

(left + right)

**TSA of cuboid =

2 (l b + bh + h l)

.**
**LSA of cuboid =

2 h (l + b)

** — only the four side walls, used for room painting (not floor/ceiling).

Special case (cube,

l = b = h = s

): TSA =

6 s^{2}

, LSA =

4 s^{2}

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