Question

the dimensions of a room are 6m ×4m×4.5m it has to be papered with wallpaper 75cm wide.what is the length of wallpaper required also find the cost of wallpaper at the rate of ₹4.75 per m square
please give step by step answer​

Answer 1

Given,

The dimensions of a room are 6m ×4m×4.5m. It has to be papered with wallpaper 75cm wide.

To find,

What is the length of wallpaper required also find the cost of wallpaper at the rate of ₹4.75 per m square .

Solution :

Dimensions of room are :

Length = 6 m

Breadth = 4 m

Height = 4.5 m

As we know that wallpaper is to be covered in walls, so finding area of 4 walls :

$\longmapsto\sf Area \ of \ 4 \ walls = 2(l + b) \times h \\\\ \\ \longmapsto\sf Area \ of \ 4 \ walls = 2(6 + 4) \times 4.5 \\\\ \\ \longmapsto\sf Area \ of \ 4 \ walls = 2 \times 10 \times 4.5 \\\\ \\ \longmapsto{\bold{Area \ of \ 4 \ walls = 90 \ m^2 }}}$

Now, width of wallpaper = 75 cm = 0.75 m

$\longmapsto\sf Length \ of \ wallpaper = \dfrac{Area}{Width} \\\\ \\ \longmapsto\sf Length \ of \ wallpaper = \dfrac{90}{0.75} \\\\ \\ \longmapsto\bold{Length \ of \ wallpaper = 120 \ m} \ \star$

Now cost of wallpaper :

$\longmapsto\sf Cost \ of \ wallpaper = Rate \times length \\\\ \\ \longmapsto\sf Cost \ of \ wallpaper = 4.75 \times 120 \\\\ \\ \longmapsto\bold{Cost \ of \ wallpaper = Rs. \ 570 }$

Therefore,

Length of wallpaper required is 120 m and cost of wallpaper is Rs.570.

Answer 2

Answer:

120, ₹570

Step-by-step explanation:

Dimension of room are:

l=6m

b=4m

h=4.5m

As we know that wallpaper to be covered in walls,so finding area of 4 walls

2(l+b)*h

2(6+4)*4.5

2(10)*4.5

20*4.5

90m^2

Now, width of wallpaper =75cm

change in m = 0.75m

length of wallpaper= area/width

length of wallpaper = 90/0.75

length of wallpaper = 120m

Now cost of wallpaper

cost if wallpaper = rate * length

cost of wallpaper = 4.75* 120

cost of wallpaper= ₹570

Therefore

length of wallpaper required is 120m and cost of wallpaper is Rs 570