A class room is `7m long, 6. 5 m wide and `4m` high` . It has one door `3mxx 1. 4 m ` and three windows, each measuring `2m xx 1 mdot` The interior wall are to be colour washed. The contractor charge `R s .5.25 p e rs qdotmdot ` Find the cost of colour washing.

Explanation

dimension of classroom is

`l=7m`,`b=6.5`,`h=4m`

area of interior wall`= 2(lb+bh+hl)-3`(area of window)-area of door

`=2(7xx6.5+6.5xx4+4xx7)-3(2xx1)-3xx1.4`

`=188.8`

so total charge `=188.8xx5.25`

`=991.2 rupees`