18. A door of dimensions 3m by 2m is fixed on the wall of the dimensions 15m by 10m.
Find the cost of painting the wall at the rate of Rs 16.75 m².
Answers
Given :-
- For wall , Length = 15 m , Breadth = 10 m
- For door , Length = 3m , Breadth = 2m
To find :-
The cost of painting the wall at the rate of Rs 16.75 m².
Solution :-
The area of the wall=Length ×Breadth = 15 × 10 = 150 m²
The area of the door= Length × Breadth = 3 × 2 = 6 m²
The cost of painting the wall at the rate of Rs 16.75 per m² .
∴ The area of the wall - the area of the door = 150 - 6 = 143 m² = The area of the new wall
So , the area of the new wall = 144 m²
For 143 m² it would cost = 144 × 16.75 = Rs.2412
∴ The cost of painting the wall at the rate of Rs 16.75 m² is Rs. 2412
Step-by-step explanation:
Given length of the door
= 3 m Also given that breadth of the door
= 2 m Side of the wall
= 10 m
We know that Area of the square
= (Side)2 Area of the wall
= Side x Side
= 10 m x 10 m
= 100 m2 We know that the area of the rectangle
= length x breadth Area of the door
= Length x Breadth = 3 m x 2 m = 6 m
Thus, required area of the wall for painting
= Area of the wall – Area of the door
= (100 – 6) m2
= 94 m2
Rate of painting per square metre
= Rs. 2.50
Hence, the cost of painting the wall
= Rs. (94 x 2.50)
= Rs. 235