Early payment rebate: Paying an electricity bill before the due date gives a 4% reduction. A person saved ₹13 by early payment. What was the original bill amount?

Introduction / Context:
Percentage reductions translate to a fixed saving when applied to a base amount. Here, a 4% rebate produced a known rupee saving; we back-calculate the original bill by dividing the saving by the rate as a decimal.

Given Data / Assumptions:

• Rebate rate = 4% = 0.04
• Saving amount = ₹13

Concept / Approach:
Saving = Rate * Original Amount. Thus, Original Amount = Saving / Rate. No compounding is involved—this is a direct single reduction.

Step-by-Step Solution:
Let B be the bill amount. Then 0.04 * B = 13B = 13 / 0.04 = 325

Verification / Alternative check:
4% of ₹325 is ₹13; paying early reduces the bill by ₹13, consistent with the statement.

Why Other Options Are Wrong:
Other amounts do not yield ₹13 when 4% is computed; quick mental math shows the discrepancy.

Common Pitfalls:
Using 4 as the divisor instead of 0.04; always convert the percent to a decimal.

Final Answer:
₹ 325