Question

A door of length 4 m and breadth 3m is fixed in a square wall of length 5 m. Find the cost of painting, if the rate of painting the wall is ₹10 per square metre and the door is ₹40 per square metre.

• A. ₹130
• B. ₹480
• C. ₹610
• D. ₹710

Answer 1

The correct option is C ₹610

The length of the door 'l' = 4 m
The breadth of the door 'b' = 3 m
The length of the square wall 'a' = 5 m
The area of the door = l × b = 4 × 3 = 12 $m^2$
The area of the square wall = a × a = 5 × 5 = 25$m^2$
The area of the wall to be painted = area of the wall - area of the door = 25 – 12 = 13$m^2$
The cost of painting the wall = Area × Cost = 13 × 10 = ₹130
The cost of painting the door = Area × Cost = 12 × 40 = ₹480
The total cost of painting the wall and the door = ₹130 + ₹480
= ₹610