Question

13. The dimensions of a hall are 18m X 12m X h. Two times the area of the floor is equal to
the lateral surface area of the hall. Find its height. Also, find the cost of while washing
the 4 walls and the ceiling @ Rs. 15/m2.

Answer 1

Answer:

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.