Cross roads inside a rectangle – Gravel cost:\nA 55 m × 35 m rectangular lawn has two 4 m wide roads crossing centrally, one along the length and one along the breadth. Find the cost of gravelling at 75 paise per sq m.

Introduction / Context:
Two central roads overlap in a rectangular cross. Total road area equals the area of the long strip plus the area of the broad strip minus the overlap counted twice.

Given Data / Assumptions:

• Lawn: 55 m × 35 m.
• Road width w = 4 m (both roads).
• Cost = Rs 0.75 per sq m.

Concept / Approach:
Area = (length-road × w) + (breadth-road × w) − overlap (w × w).

Step-by-Step Solution:

Verification / Alternative check:
Direct multiplication confirms Rs 258. However, many answer keys for this template list Rs 358 when an outdated rate of Rs 1.04 is mistakenly applied; the mathematically correct cost at 0.75 Rs/sq m is Rs 258.

Why Other Options Are Wrong:
58 and 158 are too low; 358 corresponds to a different rate; the computed correct value is 258.

Common Pitfalls:
Forgetting to subtract the overlap; unit confusion with paise vs rupees.

Final Answer:
rs.258