Question

A cuboidal metal block of dimensions $20$ cm $\times$ $16$ cm $\times$ $12$ cm weighs $6$ kg. Find the weight of block of the same metal of size $10$ cm $\times$ $8$ cm $\times$ $8$ cm.

• A. $3$ kg
• B. $8$ kg
• C. $7$ kg
• D. $1$ kg

Answer 1

The correct option is D $1$ kg

The dimensions of the cuboidal metal block are $20cm,16cmand12cm$

Volume of cuboid $=length\times breadth\times height$ (Product of all three dimensions)

Volume of metal block$=20\times 16\times 12=3840c{m}^3$

The weight of $3840c{m}^3=6kg$ (Given)

$\therefore$The weight of $1c{m}^3=\frac{6}{3840}$(By unitary method)

To find the weight of the metal block with dimensions $10cm,8cmand8cm$, we first need to find its volume.

Volume=$10\times 8\times 8=640c{m}^3$

We know that,

The weight of $1c{m}^3=\frac{6}{3840}$

$\therefore$The weight of $640c{m}^3=\frac{6}{3840}\times 640=1kg$ (By unitary method)