A person deposited ?500 for 3 years, ?650 for 5 years, and ?1,250 for 7 years. He received a total simple interest of ?1,620. The rate of interest per annum is:
This questions was previously asked in
Combined Graduate Level Examination Tier I 2023
Explanation:
- To find the rate of interest, we use the formula for simple interest: \( \text{SI} = \frac{P \times R \times T}{100} \).
- Combine interests from all deposits:
- For ?500 for 3 years: \( \frac{500 \times R \times 3}{100} \)
- For ?650 for 5 years: \( \frac{650 \times R \times 5}{100} \)
- For ?1,250 for 7 years: \( \frac{1250 \times R \times 7}{100} \)
- Add equations: \( \frac{500 \times R \times 3}{100} + \frac{650 \times R \times 5}{100} + \frac{1250 \times R \times 7}{100} = 1620 \).
- Simplifying gives: \( 15R + 32.5R + 87.5R = 1620 \rightarrow 135R = 1620 \).
- Solving for R yields: \( R = 12\% \).
- Correct Answer: Option 1 - 12%.
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By: Parvesh Mehta