The length, breadth and height of a cuboid are 8cm, 7 1/2 cm and 6 1/2 cm respectively. What Is its volume in…

Analyze the question: We need the volume of a cuboid whose dimensions are in cm, then convert it to m³ and write it in standard form.

Concept: Volume of a cuboid = length × breadth × height. Conversion: 1 cm = 10⁻² m, so 1 cm³ = (10⁻²)³ m³ = 10⁻⁶ m³.

Solution:

Volume = 8 × 7.5 × 6.5

• 8 × 7.5 = 60
• 60 × 6.5 = 390 cm³

Convert to m³:

390 cm³ = 390 × 10⁻⁶ m³ = 3.9 × 10² × 10⁻⁶ = 3.9 × 10⁻⁴ m³

Answer: The volume is 3.9 × 10⁻⁴ m³, which is option D.

Tip: When converting cm³ to m³, always multiply by 10⁻⁶, not 10⁻². Length units are cubed when you move to volume. A quick check: 390 cm³ is a very small volume, so a small power like 10⁻⁴ makes sense.