Question

The walls and the ceiling of a room 7 m long , 5 m wide and 3.5 m high are covered with paper 6 dm wide. Find the length of a paper required , if no length less than a metre can be bought

Answer 1

l = 7 m, b = 5 m and h = 3.5 m

Area of four walls = 2(l + b)h = 84 m2

Let the length of the paper be L.

L × 6/10 = 84

L = 140 m

Length of the paper required is 140 m.

Answer 2

Answer: The length of a paper required is 198.33 meters.

Step-by-step explanation:

Since we have given that

Length of room = 7 m

Width of room = 5 m

Height of room = 3.5 m

So, Area of 4 walls and the ceiling would be

$2(l+b)\times h+l\times b\\\\=2(7+5)\times 3.5+7\times 5\\\\=2\times 12\times 3.5+35\\\\=84+35\\\\=119\ m^2$

If the width of paper = 6 dm = 0.6 m

So, Area of 4 walls + Area of ceiling = Area of paper

$119=0.6\times l\\\\\dfrac{119}{0.6}=l\\\\198.33=l$

Hence, the length of a paper required is 198.33 meters.