Surface area

Geometry Level 3

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. 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?


The answer is 7.

Akash Dhasmana by akash dhasmana , 20, India

This section requires Javascript.
You are seeing this because something didn't load right. We suggest you, (a) try refreshing the page, (b) enabling javascript if it is disabled on your browser and, finally, (c) loading the non-javascript version of this page . We're sorry about the hassle.

1 solution

Ishaan Shanker
May 10, 2016

Surface area of the box = 2 ( l b + b h + l h ) = 2 ( 80 × 40 + 40 × 20 + 80 × 20 ) = 2 × 5600 cm 2 2(lb+bh+lh) = 2(80 \times 40 + 40 \times 20 +80 \times 20) =2 \times 5600 \text{ cm}^2

Area of 1 sheet of paper = 40 × 40 cm 2 40 \times 40 \text{ cm}^2

No. of papers req. = 2 × 5600 40 × 40 = 7 \dfrac{2 \times 5600}{40 \times 40} = 7

1 Helpful 0 Interesting 0 Brilliant 0 Confused

Thanks for sharing your approach, Ishaan! I upvoted your solution. (+1)

Please enclose only math formulae, and not other text in the Latex brackets. I have edited your solution accordingly.

Pranshu Gaba - 5 years, 1 month ago

0 pending reports

×

Problem Loading...

Note Loading...

Set Loading...