Unitary method with dozens: If 15 eggs cost ₹ 75, find the cost of 4 dozen eggs (48 eggs).

Introduction / Context:
Here we convert a partial-dozen cost to a multiple-dozen cost using direct proportion. A dozen equals 12 units, so 4 dozens = 48 units. The unitary method is ideal for this conversion.

Given Data / Assumptions:

• 15 eggs → ₹ 75 total.
• Find cost for 4 dozens = 48 eggs.

Concept / Approach:
Find the price per egg and multiply by 48. Because costs are linear here, proportional scaling is valid.

Step-by-Step Solution:

Verification / Alternative check:
Scaling: From 15 to 48 is a factor of 48/15 = 3.2, so the cost should scale to 75 × 3.2 = ₹ 240, identical to the unit-price computation.

Why Other Options Are Wrong:

• ₹ 300: Would imply ₹ 6.25 per egg, inconsistent with the given rate.
• ₹ 150 or ₹ 185: Too low relative to the direct proportion result.

Common Pitfalls:
Using 4 × 15 instead of 4 × 12 for “four dozens,” or forgetting to convert dozens to units correctly. Always translate dozens to absolute counts before applying proportions.

Final Answer: