Question

a door of length 2 metre and breadth 1 metre is fitted in a wall the length of the wall is 4.5 metre and the breadth is 3.6 metre as shown in the figure alongside find the cost of whitewashing the wall if the rate of whitewashing the wall is 20 metre square​

Answer 1

Answer:

• The cost of white washing will Rs. 284.

Step-by-step explanation:

Given:

• Length of door = 2 m
• Breadth of door = 1 m
• Length of wall = 4.5 m
• Breadth of wall = 3.6 m
• Rate of white washing = Rs. 20 per m²

To Find:

• Total cost of white washing of wall.

Formula used:

• Area of rectangle = l × b

Now, Area to be white washed = Area of wall - Area of door.

First we will find area of wall,

⇒ Area of wall = l × b

⇒ Area of wall = 4.5 × 3.6

⇒ Area of wall = 16.2 m²

Now, we will find area of door,

⇒ Area of door = l × b

⇒ Area of door = 2 × 1

⇒ Area of door = 2 m²

So, Area to be white washed = Area of wall - Area of door

⇒ Area to be white washed = 16.2 - 2

⇒ Area to be white washed = 14.2 m²

Now, it is given that,

∴ Cost of white washing = Rs. 20 per m²

So, cost of white washing of 14.2 m² is:

⇒ 20 × 14.2

⇒ Rs. 284

Hence, the cost of white washing will Rs. 284.

Answer 2

$\sf\Large{\underline{\underline{Solution:-}}}$

$\underline{\sf{\red{Find:-}}}$

• The cost of whitewashing the wall if the rate of whitewashing the wall is 20 metre square.

$\underline{\sf{\green{Where,,}}}$

• Length of door = 2m
• Breadth of door = 1m
• length of wall = 4.5m
• Breadth of wall = 3.6m
• Rate of whitewashing = 20m²

So,

First, find the Area of door.

We know,

Area = $\bf{\underline\blue{length \: × \: Breadth}}$

• Substitute the values.

$\Longrightarrow$Area = 2m × 1m

$\Longrightarrow$Area = 2m²

∴The area of door is 2m²

$\underline{\sf{\pink{Now,}}}$

Find the Area of wall.

$\Longrightarrow$Substitute the values.

$\Longrightarrow$Area = 4.5m × 3.6m

$\Longrightarrow$Area = 16.2

∴The area of wall is 16.2m².

$\underline{\sf{\green{Therefore,}}}$

$\Longrightarrow$Area need to be white washed = Area of Wall - Area of door.

$\Longrightarrow$Area need to be white washed = 16.2m² - 2m²

∴Area need to be white washed = 14.2m²

$\underline{\sf{\pink{Now,}}}$

• We know that the cost of whitewashing the wall is 20m².

$\Longrightarrow$So, Area required to be white washed = 14.2m²

$\Longrightarrow$Since, Cost of white washing = 14.2 × 20

= ₹ 284

$\underline{\sf{\purple{Hence,}}}$

∴The cost of white washing is ₹ 284.