Question

Mary wants to decorate her Christmas tree. She wants to place the tree on a wooden box covered with coloured paper with picture of Santa Claus on it . If the box has length, breadth and height as 80 cm, 40 cm and 20 cm respectively. How many dimensions does the coloured paper has? ​

Answer 1

Answer:

Given that mary wants to paste the paper on the outer surface of the box. The quantity of the paper required would be equal to the surface area of the box which is of the shape of cuboid. The dimension of the box are  

Length l=80 cm

Breath b=40 cm

Height h=20 cm

Surface area of the box =2[lb+bh+hl]

                                       =2[80×40+40×20+20×80]

                                       =2×5600

                                       =11200 cm  

2

 

Area of each sheet of paper =40×40

                                               =1600 cm  

2

 

∴ Number of sheets required =  

1600

11200

​  

 

                                                 =7

Step-by-step explanation:

Answer 2

Answer:

Mary would require 7 sheets.

Step-by-step explanation:

Given :-

Length = 80 cm

Breadth = 40 cm

Height = 20 cm

Side of each sheet of paper = 40 cm

To find :-

Number of sheets required

Solution

Mary wants to past paper on outer surface area of the box, its is in shape of cuboid, so we shall consider and find surface area of cuboid/box.

Surface area of box = 2(lb + bh + hl)

• 2[(80 × 40) + (40 × 20) + (20 × 80)] cm²

• 2[3200 + 800 + 1600]cm²

• 2[5600]cm²

• 11200 cm²

Area of each sheet of paper = side × side

• 40 × 40 cm²

• 1600 cm²

Number of sheets required = $\frac{Surface\;area\;of\;box}{area\;of\;each\;sheet\;of\;paper}$

• $\frac{11200}{1600}$

• $7$

∴ Mary would require 7 sheets.