Description : The length, breadth and height of a room are 5 m, -Maths 9th
Last Answer : Area of four walls = 2h (l + b) Here, l = 5 m, b = 4 m and h = 3 m Area of four walls = 2 x 3(5 + 4) = 54 m2 Area of ceiling = l x b = 5 x 4 = 20 m2 Total area to be white-washed = 54 + 20 = 74 m2 Cost of white-washing of 1 square metre = ₹ 7.50 ∴ Cost of white-washing = ₹74 x 7.50 = ₹ 555.