The difference between the simple interests received from two different sources on Rs 2000 for 3 years is Rs 15. What is the difference between their rates of interest?
Answer & explanation
Correct answer: option 4
The correct answer is Option (4) → 0.25%
Simple interest is \(\displaystyle \mathrm{SI}=\frac{P\times R\times T}{100}\). With the same principal and time, the difference in interest comes only from the difference in rates.
Principal \(P=\) Rs 2000, time \(T=3\) years, difference in interest \(=\) Rs 15
Let the difference in rates be \(d\%\); then \(\displaystyle \frac{2000\times d\times3}{100}=15\)
\(60d=15\)
\(\displaystyle d=\frac{15}{60}=0.25\)
The rates differ by 0.25%.