Question

A room is 11 m long, 8 m broad. It has two windows each measuring 2 m by 1 m and two doors each measuring 1.5 m by. 5 m. If the height of the room is 15 m,then find the cost of painting its four walls at rupees 5 per square meter.

Answer 1

Answer:

A room is 8.5 m long 6.5 m broad and 3.4 m high it has two doors each measuring 1.5 my by 1m and two windows each measuring 2m by 1m .find the cost of painting its four walls at rupees 160 per metre square

Given the room dimension is 8.5 m by 6.5 m by 3.4 m

There are 2 doors.

Each door is 1.5 m by 1 m.

There are 2 windows.

Each window is 2 m by 1 m.

To Find:

The cost of painting its 4 walls at Rs 160 per m²

Solution:

Find the area of the 4 walls including the doors:

Area of the 4 walls = 2(8.5 + 6.5) x 3.4

Area of the 4 walls = 102 m²

Find the area of the two doors:

1 door = 1.5 x 1

1 door = 1.5 m²

2 doors = 1.5 x 2

2 doors = 3 m²

Find the area of the two windows:

one window = 2 x 1

one window = 2 m²

two windows = 2 x 2

two windows = 4 m²

Find the area of the 4 walls without the doors:

Area = 102 - 3 - 4

Area = 95 m²

Find the cost:

1 m² = Rs 160

95 m² = 95 x 160

95 m² = Rs 15,200

Answer: The cost is Rs 15,200

Answer 2

Your Answer:

We have to paint the four walls of the room

So, Length of room = 11 m

Breadth = 8m

Height = 15m

So, Lateral Surface area of room = 2(l+b)h

So, CSA = 2(11+8)15

=> CSA = 38 * 15

=> CSA = 570m^2

And the parts to subtract

= area of two doors + area of two window

= 2(1.5 * 5) + 2(2*1)

= 2( 7.5 ) + 4

= 15 + 4

= 19

Parts to paint = 570 - 19 = 551m^2

So, Cost of painting = 5 * 551

=> Cost of painting = 2755 rupees

So, Cost of painting the room is 2755 rupees