Govt. Exams
Entrance Exams
Wait, recalculating: Suresh's SI = (15000 × 7 × 1.5) / 100 = ₹1,575.
Amit's SI = (12000 × 9 × 2) / 100 = ₹2,160.
Difference = ₹585.
Let me verify options...
Actually Difference = 2160 - 1575 = ₹585, but this doesn't match.
Rechecking: (15000×7×1.5)/100 = 1575; (12000×9×2)/100 = 2160.
Difference = 585.
There seems to be an issue with my options.
Amit earned ₹585 more.
So option A is closest.
In simple interest problems, the difference in amounts over different time periods reveals the interest earned, which we can use to find the principal and rate.
Step 1: Find the interest earned between the two periods
The amount after 2 years is ₹7,200 and after 3.5 years is ₹8,400.
Step 2: Calculate the annual simple interest rate
Since ₹1,200 is earned in 1.5 years, the annual interest is:
Step 3: Find the principal using the first condition
Using the simple interest formula: \(A = P + I\), where \(A\) is the amount, \(P\) is the principal, and \(I\) is total interest.
After 2 years:
Step 4: Verify with the second condition
After 3.5 years, total interest = \(800 \times 3.5 = ₹2,800\)
Amount = \(5,600 + 2,800 = ₹8,400\) ✓
Answer: The principal amount is ₹5,600 (Option D)
