Question

A room 8 m long. 6 m wide and 4 m high has two windows ench 1.5 m x 1 m and two
doors each 2.2 mx 1.2 m. Find the cost of whitewashing the walls at 3 per sq. metre.​

Answer 1

Answer:

here is ur answer

hope it will help u☺️

Step-by-step explanation:

Given:

A room is 8.5 m long 6.5 m broad and 3.4 m high it has two doors each measuring 1.5 m by 1 m and two windows each measuring 2 m by 1 m .

To Find:

Find the cost of painting its four walls at rupees 160 per metre².

Solution:

Room walls

Length of room = 8.5 m

Breadth of room = 6.5 m

Height of room = 3.4 m

We know the formula of surface area of four walls of room:

Surface area of four walls = 2 (Length + breadth)×Height

Surface area of four walls = 2 (8.5 + 6.5)×3.4 = 102 m²

Doors

Length of door = 1.5 m

Breadth of door = 1 m

Shape of door is in rectangle, we know the formula of area of rectangle:

Area of rectangle = Length × breadth

Means:

Area of each door = Length × breadth

Area of each door = 1.5 × 1 = 1.5 m²

So area of two doors will be:

Area of both door = 1.5 × 2 = 3.0 m²

Windows

Length of window = 2.0 m

Breadth of window  = 1 m

Shape of window  is in rectangle, we know the formula of area of rectangle:

Area of rectangle = Length × breadth

Means:

Area of each window  = Length × breadth

Area of each window  = 2.0 × 1 = 2.0 m²

So area of two window  will be:

Area of both window  = 2.0 × 2 = 4.0 m

Now net area of wall will become:

Net area of wall=Area of four walls-Area of door -Area of window

Net area of wall = 102 - 3.0 - 4.0 = 95 m²

Cost of painting

Cost of painting will be:

Cost = Price rate× Area

Cost = 160× 95

Cost =  15200 Rs.

Means the cost of painting its four walls is 15200 Rupees.

Answer 2

Answer:

area of walls to be whitewashed = area of walls − area of doors and Windows

=2h(l+b)−2×2.5−1.5×2

264−5−3

=256m

2

cost of whitewash =256×3.2

=819.2rs