Question

A hall of 12m, breadth 15m ,and height 5m is to be fixed with wall paper on all the four walls. If the cost of fixing the wall paper is Rs 45 per square metre, how much will it cost?
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Answer 1

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It is given that length, breadth and height of a room are 8 m, 5 m and 3 m respectively.

Area of four walls of the room is: 2h(l+b)

A=2h(l+b)=2×3(8+5)=6×13=78 m^2

Area of the ceiling is:

A=l×b=8×5=40 m^2

Total area of the four walls and the ceiling of the room is 78+40=118 m^2

It is given that cost of white washing is Rs.15/m^2

, therefore,

Total cost of white washing is:

118×15=1770

Hence, the cost of white washing the walls is Rs.1770.

Answer 2

It is given that length, breadth and height of a room are 8 m, 5 m and 3 m respectively.

Area of four walls of the room is: 2h(l+b)

A=2h(l+b)=2×3(8+5)=6×13=78 m

2

Area of the ceiling is:

A=l×b=8×5=40 m

2

Total area of the four walls and the ceiling of the room is 78+40=118 m

2

It is given that cost of white washing is Rs.15/m

2

, therefore,

Total cost of white washing is:

118×15=1770

Hence, the cost of white washing the walls is Rs.1770.