The wall of a room is 16 long and 6 m high. There is a long rectangular window in the wall measuring 3 m long and I m high. Find the cost of painting the wall at the rate of Rs 15 per sq. m.

Answer

To solve the problem step by step, we will calculate the area of the wall, the area of the window, and then find the cost of painting the wall after subtracting the area of the window.

### Step 1: Calculate the area of the wall
The area of a rectangular wall can be calculated using the formula:
\[ \text{Area} = \text{Length} \times \text{Height} \]

Given:
- Length of the wall = 16 m
- Height of the wall = 6 m

So, the area of the wall is:
\[ \text{Area of the wall} = 16 \, \text{m} \times 6 \, \text{m} = 96 \, \text{m}^2 \]

### Step 2: Calculate the area of the window
The area of a rectangular window can also be calculated using the same formula:
\[ \text{Area} = \text{Length} \times \text{Height} \]

Given:
- Length of the window = 3 m
- Height of the window = 1 m

So, the area of the window is:
\[ \text{Area of the window} = 3 \, \text{m} \times 1 \, \text{m} = 3 \, \text{m}^2 \]

### Step 3: Calculate the area to be painted
To find the area that needs to be painted, we subtract the area of the window from the area of the wall:
\[ \text{Area to be painted} = \text{Area of the wall} - \text{Area of the window} \]

So, we have:
\[ \text{Area to be painted} = 96 \, \text{m}^2 - 3 \, \text{m}^2 = 93 \, \text{m}^2 \]

### Step 4: Calculate the cost of painting
The cost of painting is calculated by multiplying the area to be painted by the cost per square meter:
\[ \text{Cost} = \text{Area to be painted} \times \text{Cost per sq. m} \]

Given:
- Cost per sq. m = Rs 15

So, the cost of painting is:
\[ \text{Cost} = 93 \, \text{m}^2 \times 15 \, \text{Rs/m}^2 = 1395 \, \text{Rs} \]

### Final Answer
The cost of painting the wall is Rs 1395.

---