Question

A door of length 5m and breadth 4m is fitted in a wall. the length of the wall is 20m and the breadth is 15m. find the cost of white washing the wall, if the rate of white washing the wall is ₹10 per sq m​

Answer 1

Answer:

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.

Answer 2

Answer:

Rs 2800

Step-by-step explanation:

Area of wall = Length × Breadth

= 20m×15m

= 300 sq m

& Area of door = l×b= 5m×4m= 20 sq m

Now

area of wall for white washing = 300 - 20 sq m

= 280 sq m

If the cost of white washing per square m = RS 10

then for 280 sq m = 280×10 = Rs 2800