Question

A door of length 18m and breadth 20 m is fitted in a wall. The length of the wall is 62m and the

breadth is 42 m. Find the cost of white washing the wall , if the rate of white washing the wall is ₹55.20

per square metre?​

Answer 1

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

2

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

2

Now, Area of wall excluding door

=Area of wall including door−Area of door

=16.2−2=14.2m

2

Since, The rate of white washing of 1m

2

the wall=Rs. 20

Therefore, the rate of white washing of 14.2m

2

the wall=20×14.2

=Rs. 284

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