Simple Interest – Comparing two scenarios to find the principal: For a certain principal S, the simple interest in 2 years at 8% per annum is ₹ 110 more than the simple interest in 1 year at 5% per annum (on the same S). Find S.
Aptitude
Simple Interest
Difficulty: Easy
Choose an option
Answer
Correct Answer: ₹ 1000
Explanation
Introduction / Context:We compare two simple-interest amounts for the same principal under different time-rate pairs.
Given Data / Assumptions:
- SI1 = S * 8% * 2 = 0.16 S
- SI2 = S * 5% * 1 = 0.05 S
- SI1 - SI2 = ₹ 110
Concept / Approach:Set up the difference equation and solve for S.
Step-by-Step Solution:0.16 S - 0.05 S = 110 → 0.11 S = 110 → S = 1000
Verification / Alternative check:SI1 = ₹ 160; SI2 = ₹ 50; difference = ₹ 110 (checks).
Why Other Options Are Wrong:₹ 5000, ₹ 1050, ₹ 950 do not satisfy the difference condition.
Common Pitfalls:Misinterpreting 8% for 2 years as 8% total.
Final Answer:₹ 1000