Question

if a box has a length 80cm ,breadth 40cm and height 20cm respectively.How many square sheets of paper of side 40cm would be required to cover it?

Answer 1

Since ,
Quantity of paper
required would be equal to the surface area of the box which is of the shape of a cuboid. The dimensions
of the box are:

Length =80 cm, Breadth = 40 cm, Height = 20 cm.
The surface area of the box = 2(lb + bh + hl)
= 2[(80 × 40) + (40 × 20) + (20 × 80)] cm2
= 2[3200 + 800 + 1600] cm2
= 2 × 5600 cm2 = 11200 cm2
The area of each sheet of the paper = 40 × 40 cm2
= 1600 cm2
Therefore, number of sheets required =
surface area of box
area of one sheet of paper
=
11200/ 1600
= 7
So, she would require 7 sheets.