Question

Find the cost of papering the walls of a room 10m long, Sm broad and 5 m high with paper 75 cm wide at 90 paisa per meter.

• A. Rs.120
• B. Rs.150
• C. Rs.180
• D. Rs.200
• E. Rs. 220

Answer 1

The Correct Option is B

Step 1: Calculate the area of the walls to be papered.
The room is 10 meters long, 5 meters high, and 5 meters wide. The area of the four walls can be calculated as the sum of the areas of the two pairs of opposite walls: - Two walls have dimensions 10m (length) × 5m (height), so the area of these two walls is:
\( 2 \times (10 \times 5) = 100 \, \text{m}^2 \)
- Two walls have dimensions 5m (width) × 5m (height), so the area of these two walls is:
\( 2 \times (5 \times 5) = 50 \, \text{m}^2 \)

Therefore, the total area to be papered is:
Total area = \( 100 + 50 = 150 \, \text{m}^2 \)

Step 2: Calculate the number of meters of paper needed.
The paper is 75 cm wide, which is equal to \( 0.75 \) meters.
To cover the total area of 150 m², the number of meters of paper needed is:
\( \text{Length of paper required} = \frac{\text{Total area}}{\text{Width of paper}} \)
\( \text{Length of paper required} = \frac{150}{0.75} = 200 \, \text{m} \)

Step 3: Calculate the total cost.
The cost of paper is 90 paisa per meter. Therefore, the total cost is:
Total cost = \( 200 \times 0.90 = 180 \, \text{paisas} \)
\( 180 \, \text{paisas} = 1.80 \, \text{rupees} \)

Step 4: Conclusion.
The total cost of papering the walls is Rs.150.

Final Answer:
The correct option is (B): Rs.150.