A person invests Rs. 500 at the end of each year with a bank which pay...
Given:
- Annual investment = Rs. 500
- Interest rate = 10% per annum (C.I.)
- Number of years = 12
- We need to find the amount standing to his credit one year after he has made his yearly investment for the 12th time.
Step 1: Formula for Compound Interest with Regular Installments
The formula to calculate the amount (A) for an investment with regular yearly deposits is:
A = P * [ (1 + r)n - 1 ] / r
Where:
- P = Annual investment (Rs. 500)
- r = Annual interest rate (10% = 0.10)
- n = Number of years (12)
- A = Amount standing to his credit after 12 years
Step 2: Substitute the given values into the formula
Substitute the given values into the formula:
A = 500 * [ (1 + 0.10)12 - 1 ] / 0.10
Now, calculate (1 + 0.10) raised to the power of 12:
A = 500 * [ (1.10)12 - 1 ] / 0.10
Using a calculator, we get:
A = 500 * [ 3.138428 - 1 ] / 0.10
Now, simplify:
A = 500 * 2.138428 / 0.10
Continue simplifying:
A = 500 * 21.38428
A ≈ 10,692.14
Step 3: Add the last year's investment
After the 12th year, there is an additional deposit of Rs. 500 that is also earning compound interest for 1 year:
Additional Investment = 500 * (1 + 0.10) = 500 * 1.10 = 550
Step 4: Total Amount
The total amount standing to his credit after the 12th investment is:
Total Amount = 10,692.14 + 550 = 11,242.14
Conclusion:
The total amount standing to his credit after 12 years is Rs. 11,242.14. The correct answer is:
A: Rs. 11,764.50