Question

The breadth of a cuboid is 2 less than its length and it's height is one less than its breadth. If the surface area of cuboid is 188m²,find its volume.

Answer 1

the surface area of a cuboid is 1792 cm if its length , breadth and height are in the ratio 4:2:1 then find the length of the  ..

Answer 2

Answer:

Step-by-step explanation:

Let the length be l.

Breadth = l - 2

Height = l - 2 - 1 = l - 3

SURFACE AREA :

2 × l × (l - 2) = 2l^2 - 4l

2 × l × (l - 3) = 2l^2 - 6l

2 × (l - 2)(l - 3) = 2(l^2 - 5l + 6) = 2l^2 - 10l + 12

We add these as follows :

2l^2 - 4l + 2l^2 - 6l + 2l^2 - 10l + 12

6l^2 - 20l + 12 = 188

6l^2 - 20l - 176 = 0

Divide through by 2:

3l^2 - 10l - 88 = 0

The roots are : - 22 and 12

3l^2 + 12l - 22l - 88 = 0

3l(l + 4) - 22(l + 4) = 0

(3l - 22)(l + 4) = 0

3l = 22

l = 22/3 m

or l = - 4

We take the positive value.

l = 22/3

Breadth = 22/3 - 2 = 16/3

Height = 22/3 - 3 = 15/3

Volume = length × width × height

22/3 × 16 /3 × 15/3 = 1760/9 m ^3

= 195.555 m cubed.