The cost of preparing the walls of room 12m long at the rate of Rs. 1.35 per square metre is RS. 340.20 and the cost of matting the floor at 85 paise per square metre is Rs. 91.80. Find the height of the room.

Explanation

Length of the room`=12 m`
Cost of matting floor`=`area of floor`xx`rate per `m^2`
Area of floor`=`Cost of matting floor`/`rate per `m^2=91.8/0.85=108 m^2`
Breadth of floor`=`area`/`length`=108/12=9 m`
Area of `4` walls `=` Cost of preparing walls`/`rate per `m^2=340.20/1.35=252`
Total area of walls`=2(l\+b)timesh`
`252=2(12+9)timesh`
`h=252/42=6 m`
`therefore` Height of the room`=6 m`