Gravel path inside a rectangular lawn (unit corrections applied) A rectangular grassy plot measures 110 m by 65 m. A 0.5 m wide gravel path runs all around the inside. Find the cost of gravelling the path at ₹0.80 per m².

Introduction / Context:When a uniform path runs inside a rectangle, the path area equals outer area minus inner rectangle area. Here, obvious unit typos are interpreted reasonably (metres throughout, 0.5 m path).

Given Data / Assumptions:

• Outer dimensions: 110 m by 65 m
• Path width w = 0.5 m inside on all sides
• Rate = ₹0.80 per m^2 (80 paise per m^2)

Concept / Approach:Inner rectangle dimensions reduce by 2w in each direction. Path area = Outer − Inner.

Step-by-Step Solution:

Verification / Alternative check:Approximate path area also equals perimeter * width − 4 * (w^2) for thin paths: 2(110+65)*0.5 − 4*(0.25) = 350*0.5 − 1 = 175 − 1 = 174 m^2, same result.

Why Other Options Are Wrong:₹340, ₹320, and ₹480 arise from misread unit rates or dimensions; only ₹139.20 matches the corrected interpretation and exact calculation.

Common Pitfalls:Using centimetres inadvertently or treating the cost as ₹80 per m^2 instead of ₹0.80 per m^2 drastically overstates the amount.

Final Answer:₹139.20