A classroom is 7m long, 6m broad and 3.5m high. Doors and windows occupy an area of `17\ m^2dot` What is the cost of white-washing the walls at the rate of Rs. `1. 50\ p e r\ m^2dot`

Explanation

Given
Length`=7`m
Breath`=6`m
Height`=3.5`m
Area of four walls`=2(l+b)xxh`
`=2(7+6)xx3.5`
`= 2xx13xx3.5`
`=91m^2`
Area of 4 wall without windows and doors`=91-17`
`=74m^2`
Cost of white washing`=74+1.50=`Rs,` 111`