Question

The dimensions of a room are 14 m x 10 m x 6.5 m. There are two doors and 4 windows in the room. Each door measures 2.5 m x 1.2 m and each window measures 1.5 x 1 m. Find the cost of painting the four walls of the room at ₹35 per m².

Answer 1

Dimensions of wall:

Length = 14 m

Breadth = 10 m

Height = 6.5 m

Dimensions of windows

Length = 1.5 m

Breadth = 1 m

And,

Length of doors = 2.5 m

Breadth of doors = 1.2 m

Cost = ₹35 per m²

Now,

Area of four walls = 2(Length of walls × Height of walls) + 2(Breadth of walls × Height of walls)

= 2(14 × 6.5) + 2(10 × 6.5)

= 182 + 130

= 312

⇨ Area of four walls is 312 m²

Area of two doors = 2(Length of doors × Breadth of doors)

= 2(2.5 × 1.2)

= 6

⇨ Area of two doors is 6 m²

Area of four windows = 4(Length of windows × Breadth of windows)

= 4(1.5 × 1)

= 6

⇨ Area of four windows is 6 m²

Therefore,

Area to be painted = Area of 4 walls – (Area of 2 doors + Area of 4 windows)

= 312 – (6+ 6)

= 300

⇨ Area to be painted is 300 m²

Cost of painting = 300 m² × ₹ 35 per m²

=₹10500