Question

The length, breadth, and height of a cuboid are in the ratio 5:3:2, and its total area is 3.968 cm^2. Find the dimensions of the cuboid.​

Answer 1

length of cuboid=5x

breadth of cuboid=3x

height of cuboid=2x

total area of cuboid=3.968cm^2

3.968=2(lb+bh+hl)

3.968=2(5x*3x+3x*2x+2x*5x)

3.968=2(15x+6x+10x)

3.968=2(31x)

3.968=62x

3.968/62=X

15.625=X

the dimension of the cuboid=15.625

Answer 2

Given :

The length breadth and height of a cuboid are in the ratio 5:3:2 .

Total Surface Area is 3968 cm² .

To Find :

Dimensions of the cuboid .

Solution :

$\longmapsto\tt{Let\:Length\:be=5x}$

$\longmapsto\tt{Let\:Breadth\:be=3x}$

$\longmapsto\tt{Let\:Height\:be=2x}$

Using Formula :

$\longmapsto\tt\boxed{S.A\:of\:Cuboid=2(lb+bh+hl)}$

Putting Values :

$\longmapsto\tt{3968=2(5x\times{3x}+3x\times{2x}+2x\times{5x})}$

$\longmapsto\tt{3968=2({15x}^{2}+{6x}^{2}+{10x}^{2})}$

$\longmapsto\tt{\cancel\dfrac{3968}{2}={31x}^{2}}$

$\longmapsto\tt{\cancel\dfrac{1984}{31}={x}^{2}}$

$\longmapsto\tt{\sqrt{64}=x}$

$\longmapsto\tt\bf{8=x}$

Value of x is 8 .

Therefore :

$\longmapsto\tt{Length\:of\:Cuboid=5(8)}$

$\longmapsto\tt\bf{40\:cm}$

$\longmapsto\tt{Breadth\:of\:Cuboid=3(8)}$

$\longmapsto\tt\bf{24\:cm}$

$\longmapsto\tt{Height\:of\:Cuboid=2(8)}$

$\longmapsto\tt\bf{16\:cm}$