A door of length 2 m and breadth 1 m is fitted in a wall. The length of the wall is 4.5 m and the breadth is 3.6 m. Find the cost of white washing the wall, if the rate of white washing the wall is ₹ 20 per m².

Area of rectangular door = length x breadth = 2 m x 1 m = 2 m²
Area of wall including door = length x breadth = 4.5 m x 3.6 m = 16.2 m²
Now, Area of wall excluding door
= Area of wall including door – Area of door
= 16.2 – 2 = 14.2 m²
Since, The rate of white washing of 1 m2 the wall = ₹20
Therefore, the rate of white washing of 14.2 m2 the wall = 20 x 14.2 = ₹284
Thus, the cost of white washing the wall excluding the door is ₹284.

Class 7 Maths Chapter 11 Exercise 11.1

for more answers vist to:
https://www.tiwariacademy.com/ncert-solutions/class-7/maths/chapter-11/