The dimensions of a room are 12.5 m by 9m by 7m. There are 2 doors and 4 windows in the room; each door measures 2.5 m by 1.2 m and each window 1.5m by 1 m. Find the cost of painting the walls at Rs. 3.50 per square metre.

Explanation

Dimension of room`=12.5 mtimes9 mtimes7 m`
Dimension of door`=2.5mtimes1.2 m`
Dimension of window`=1.5mtimes1m`
Area of room`=2(l+b)h=2(12.5+9)times7=301 m^2`
Area of `2` doors`=2(2.5times1.2)=6m^2`
Area of `4` windows`=4(1.5times1)=6 m^2`
Area to be painted`=(301-12)=289 m^2`
`therefore` Cost of painting walls at rate `Rs.3.50 per m^2=3.50times289=Rs.1011.50`