A hall 36 m long and 24 m broad allowing 80 m2 for doors and windows the cost of papering the walls ...

Question

A hall 36 m long and 24 m broad allowing 80 m2 for doors and windows the cost of papering the walls at Rs 840 per m2 is Rs 9408 Find the height of the hall

Accepted Answer

Given length of the hall 36 m Breadth of the hall 24 m Let h be the height of the hall Now in papering the wall we need to paper the four walls excluding the floor and roof of the hall So the area of the wall which is to be papered Area of 4 walls 2 h I b 2 h 36 24 120 hm2 Now area left for the door and the windows 80 m2 So the area which is actually papered 120h 80 m2 Cost of papering the wall Area required for papering Cost per meter square of papering wall 9408 120 h 80 840 1120 120 h 80 1200 120 h h 10 m Hence the height of the wall would be 10 m

RD Sharma Solutions Class 7 Mathematics Solutions for Mensuration 1 Exercise 20.1 in Chapter 20 - Mensuration 1