The dimensions of a cubical box are in the ratio of 5:4:3.and the length of the diagonal is 10√2. Calculate the total surface area?

The correct answer is: 376

We have given that, dimensions of cubical box are in the ratio of 5:4:3.
Let the dimensions of the box are

Length = 5x

Breadth= 4x

Height = 3x
We have given diagonal , therefore we can write,

Lets put the assumed values of length , breadth and height in the above equation,



We can write as ,

Divide both sides of equation by 
x = 2
Therefore, the dimensions of cuboid are,
Length = 5x = 5(2)= 10

Breadth= 4x = 4(2) =8

Height = 3x=3(2)= 6

• Putting the values in the formula of surface area

Area = 2[(10)(8) + (8)(6) + (6)(10)]

= 2[80 + 48 + 60]

= 2(188)

Area =376
Therefore, the correct option is b)376.