Question

A square roomcontains 144m^3 of air.if the cost of painting its four walls at Rs 5 per square meter be RS 480,find the height of the room.

Please solve this problem fast.

Answer 1

let a be the side of square
area of 1 wall = a*h
area of 4 walls = 4a*h
area of 4walls = 480/5 = 96 m2
4ah = 96 m2
ah = 24 m2.....
volume of square room = a*a*h = 144
a* (ah) = 144
a*24= 144
a = 6 m
so h = 24/6 = 4 m