Find the area of the four walls of the room whose length is 6 m, breadth is 5 m and height is 4 m. Also find the cost of white washing of four walls, if the rate of white washing is Rs. 5 per square metre.

Answer

To find the area of the four walls of the room and the cost of whitewashing, we can follow these steps:

### Step 1: Identify the dimensions of the room
- Length (l) = 6 m
- Breadth (b) = 5 m
- Height (h) = 4 m

### Step 2: Calculate the area of the four walls
The formula for the area of the four walls of a room is given by:
\[ \text{Area of four walls} = 2h(l + b) \]

Substituting the values:
- \( h = 4 \, \text{m} \)
- \( l = 6 \, \text{m} \)
- \( b = 5 \, \text{m} \)

Now, calculate:
\[ \text{Area} = 2 \times 4 \times (6 + 5) \]
\[ = 2 \times 4 \times 11 \]
\[ = 8 \times 11 \]
\[ = 88 \, \text{m}^2 \]

### Step 3: Calculate the cost of whitewashing
The cost of whitewashing is calculated using the formula:
\[ \text{Cost} = \text{Area} \times \text{Rate} \]

Given the rate of whitewashing is Rs. 5 per square meter:
\[ \text{Cost} = 88 \, \text{m}^2 \times 5 \, \text{Rs/m}^2 \]
\[ = 440 \, \text{Rs} \]

### Final Answer:
- The area of the four walls of the room is \( 88 \, \text{m}^2 \).
- The cost of whitewashing the four walls is \( 440 \, \text{Rs} \).

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