Simple Interest – Determine rate percent from two amounts: A sum of money amounts to Rs 702 in 2 years and Rs 783 in 3 years at simple interest. Find the annual rate of interest (percent per annum).

Introduction / Context:
The difference between consecutive-year amounts under SI equals the constant annual interest. Dividing by the principal yields the rate.

Given Data / Assumptions:

• A2 = Rs 702
• A3 = Rs 783

Concept / Approach:
Annual SI = A3 - A2. Then find P from A2 = P + 2 * (annual SI). Compute r% = (annual SI / P) * 100.

Step-by-Step Solution:

Verification / Alternative check:

Why Other Options Are Wrong:

• 12% / 13% / 14% / 11%: not equal to (81 / 540) * 100.

Common Pitfalls:

• Forgetting that annual SI is the difference between adjacent yearly amounts.

Final Answer:
15% per annum.