A sum was invested on simple interest at a certain rate for 3 years. Had it been invested at 2% higher rate, it would have fetched ₹360 more interest. The value of invested sum is:
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) → ₹6000
Simple interest is \(\frac{P\times R\times T}{100}\). Raising the rate by 2% for 3 years adds interest at 2% a year for 3 years, that is, 6% of the sum, and this extra interest is the given ₹360.
Extra interest on the sum P at 2% for 3 years: \(\displaystyle \frac{P\times2\times3}{100}=\frac{6P}{100}\)
This extra interest is ₹360: \(\displaystyle \frac{6P}{100}=360\), so \(P=6000\)
The sum invested is ₹6000.