Question

Mary wants to decorate her Christmas tree. She wants to place the tree on a wooden block covered with colored paper with a picture of Santa Claus on it. She must know the exact quantity of paper to buy for this purpose. If the box has length, breadth, and height as 80 cm, 40 cm and 20 cm respectively. How many square sheets of paper of side 40 cm would she require?

Answer 1

The dimensions of the wooden block are: 

Length (l) = 80 cm 

Breadth (b) = 40 cm 

Height (h) = 20 cm 

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

= 2[(80×40)+(40×20)+(20×80)] 

= 2[5600] 

= 11200 

Surface Area of the wooden box is 11200 cm² 

The Area of each sheet of the paper = 40 x 40 cm² = 1600 cm² 

Now, 

The total number of sheets required = (Surface area of the box )/(Area of one sheet of paper) 

= 11200/1600 

= 7 

Therefore, Marry would require 7 sheets.