Simple Interest — A sum of ₹ 2668 amounts to ₹ 4669 in 5 years at simple interest. Find the annual rate of interest (percent per annum).

Introduction / Context:Here amount and principal are known over a time period, so the total simple interest and the annual rate can be computed directly.

Given Data / Assumptions:

• P = ₹ 2668.
• A = ₹ 4669.
• t = 5 years.

Concept / Approach:SI = A − P; then r = SI / (P * t).

Step-by-Step Solution:SI = 4669 − 2668 = ₹ 2001.r = 2001 / (2668 * 5) = 2001 / 13340 = 0.15.Convert to percent: r = 15% per annum.

Verification / Alternative check:Per year SI = P * r = 2668 * 0.15 = 400.2; in 5 years: 400.2 * 5 = 2001; A = 2668 + 2001 = 4669.

Why Other Options Are Wrong:They are near-misses to distract; only 15% exactly reproduces the given amount.

Common Pitfalls:Arithmetic slips when subtracting or multiplying decimals.

Final Answer:15%