Simple Interest – Find the rate given total interest: Yogesh borrowed Rs 12,000 at simple interest for 5 years. If he paid Rs 3,600 as simple interest, find the annual rate of interest (percent per annum).

Introduction / Context:
With principal, time, and total SI known, the SI rate is r = SI / (P * t). This is a standard direct-calculation problem under simple interest assumptions.

Given Data / Assumptions:

• P = Rs 12000
• t = 5 years
• SI = Rs 3600

Concept / Approach:
Compute r as a pure number (fraction), then read as percentage consistent with the options provided.

Step-by-Step Solution:

Verification / Alternative check:

Why Other Options Are Wrong:

• 5 / 8 / 10 / 7.5: do not equal the computed rate.

Common Pitfalls:

• Mistaking the units, e.g., writing 0.06% instead of 6%.

Final Answer:
6.