A wall 9 m long. 6m high and 20 cm thick is to be constructed using bricks of dimensions 30 cm. 15m and 10 cm . How many bricks will be required.?

Answer

To find the number of bricks required to construct the wall, we will follow these steps:

### Step 1: Convert all measurements to centimeters
- The wall dimensions are given in meters and centimeters. We need to convert everything to centimeters for consistency.
- Length of the wall:
\[ 9 \text{ m} = 9 \times 100 = 900 \text{ cm} \]
- Height of the wall:
\[ 6 \text{ m} = 6 \times 100 = 600 \text{ cm} \]
- Thickness of the wall:
\[ 20 \text{ cm} \text{ (already in cm)} \]

### Step 2: Calculate the volume of the wall
- The volume of the wall can be calculated using the formula for the volume of a rectangular prism:
\[ \text{Volume of the wall} = \text{Length} \times \text{Height} \times \text{Thickness} \]
Substituting the values:
\[ \text{Volume of the wall} = 900 \text{ cm} \times 600 \text{ cm} \times 20 \text{ cm} \]
\[ = 900 \times 600 \times 20 = 10800000 \text{ cm}^3 \]

### Step 3: Calculate the volume of one brick
- The dimensions of one brick are given as:
- Length: 30 cm
- Width: 15 cm
- Height: 10 cm
- The volume of one brick is calculated as:
\[ \text{Volume of one brick} = \text{Length} \times \text{Width} \times \text{Height} \]
Substituting the values:
\[ \text{Volume of one brick} = 30 \text{ cm} \times 15 \text{ cm} \times 10 \text{ cm} \]
\[ = 30 \times 15 \times 10 = 4500 \text{ cm}^3 \]

### Step 4: Calculate the number of bricks required
- To find the number of bricks required, divide the volume of the wall by the volume of one brick:
\[ \text{Number of bricks} = \frac{\text{Volume of the wall}}{\text{Volume of one brick}} \]
Substituting the values:
\[ \text{Number of bricks} = \frac{10800000 \text{ cm}^3}{4500 \text{ cm}^3} \]
\[ = 2400 \]

### Final Answer
The total number of bricks required to construct the wall is **2400 bricks**.

---