Question

The length of the wall is 8m and height is 4m. Wall is 35cm thick. There is one door of size \[2m \times 1m\] and two windows each of size \[1.20m \times 1m\]. Find the expenditure of making the wall at the rate of rupees 1500 per cubic meter.

Answer 1

Hint:
First find the volumes of all necessary objects given and then remove the volume of windows and door from the volume of the wall. Because we just have to build walls.

Complete step by step solution:
Here given that the length of wall is 8m and height is 4m, wall is 35cm=0.35m thick , also there is one door of size \[2m \times 1m\] and two windows each of size \[1.20m \times 1m\]
So it will be like,

Now let’s find the volumes one by one.
Volume of the wall = \[8m \times 4m \times 0.35m\]
\[ \Rightarrow 11.2{m^3}\]
Volume of door = \[2m \times 1m \times 0.35\]
\[ \Rightarrow 0.7{m^3}\]
Volume of the windows = \[2 \times 1.20m \times 1m \times 0.35\]
 \[ \Rightarrow 0.84{m^3}\]
But walls need to be built so we have to remove the volume of the door and window from total volume.
So, exact wall to be built = volume of wall –(volume of door + volume of windows)
\[
   \Rightarrow 11.2 - \left( {0.84 + 0.7} \right) \\
   \Rightarrow 11.2 - 1.54 \\
   \Rightarrow 9.66{m^3} \\
 \]
Total expenditure in building a wall = \[1500 \times 9.66\]
\[ \Rightarrow 14430\]

So total expenditure is rupees 14430.

Note:
Volume of doors and windows is to be subtracted because we need to calculate the expenditure of building walls only. Windows and doors would not come under construction.