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).
Aptitude
Simple Interest
Difficulty: Easy
Choose an option
Answer
Correct Answer: 6
Explanation
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:
r = 3600 / (12000 * 5) = 3600 / 60000 = 0.06 = 6Verification / Alternative check:
Annual SI = 12000 * 6% = 720; total over 5 years = 3600 (matches)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.