Simple Interest – Find the principal from total interest: The simple interest on a certain sum for 3 years at 14% per annum is Rs 235.20. Find the principal.
Aptitude
Simple Interest
Difficulty: Easy
Choose an option
Answer
Correct Answer: Rs 560
Explanation
Introduction / Context:Given SI, rate, and time, the principal is obtained using SI = P * r * t. This is a direct inversion problem under simple interest.
Given Data / Assumptions:
- SI = Rs 235.20
- r = 14% = 0.14 per annum
- t = 3 years
Concept / Approach:P = SI / (r * t).
Step-by-Step Solution:
r * t = 0.14 * 3 = 0.42P = 235.20 / 0.42 = Rs 560Verification / Alternative check:
Check SI = 560 * 0.14 * 3 = 560 * 0.42 = Rs 235.20 (matches)Why Other Options Are Wrong:
- Rs 480 / 650 / 720 / 520: do not reproduce SI = Rs 235.20 under the given rate and time.
Common Pitfalls:
- Miscalculating decimal multiplication 0.14 * 3.
Final Answer:Rs 560.