The area of 4 walls of a cuboid 400 sq. cm., its length is 15 cm and height is 8 cm. What is its breadth (in cm) ?

Options

A. a.12
B. b.20
C. c.24
D. c.10

Answer

To find the breadth of the cuboid given the area of its four walls, we can follow these steps:

### Step 1: Understand the formula for the lateral surface area of a cuboid.
The lateral surface area (area of the four walls) of a cuboid is given by the formula:
\[ \text{Lateral Surface Area} = 2H(L + B) \]
where \( H \) is the height, \( L \) is the length, and \( B \) is the breadth.

### Step 2: Substitute the known values into the formula.
Given:
- Lateral Surface Area = 400 sq. cm
- Length \( L = 15 \) cm
- Height \( H = 8 \) cm

Substituting these values into the formula:
\[ 400 = 2 \times 8 \times (15 + B) \]

### Step 3: Simplify the equation.
Calculating \( 2 \times 8 \):
\[ 400 = 16(15 + B) \]

### Step 4: Divide both sides by 16 to isolate the term with \( B \).
\[ \frac{400}{16} = 15 + B \]
Calculating \( \frac{400}{16} \):
\[ 25 = 15 + B \]

### Step 5: Solve for \( B \).
To find \( B \), subtract 15 from both sides:
\[ B = 25 - 15 \]
\[ B = 10 \text{ cm} \]

### Conclusion:
The breadth of the cuboid is \( 10 \) cm.

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