Question

a door of length 3 m and breadth one metre is fitted in a wall the length of the wall is 4.5 m and the the wall is 3.6 m find the cost of whitewashing the wall at the rate of rupees 16 per metre sq​

Answer 1

Area of rectangular door=length×breadth=2m×1m=2m2

Area of wall including door=length×breadth=4.5m×3.6m=16.2m2

Now, Area of wall excluding door

=Area of wall including door−Area of door

=16.2−2=14.2m2

Since, The rate of white washing of 1m2 the wall=Rs. 20

Therefore, the rate of white washing of 14.2m2 the wall=20×14.2

=Rs. 284

Thus, the cost of white washing the wall excluding the door is Rs. 284.