Question

Arun invests an amount of ₹4,000 at the rate of 2% simple interest per annum. For how many years did he invest the amount to double his sum?

• A. 20 years
• B. 30 years
• C. 50 years
• D. 45 years

Answer 1

The Correct Option is C

To find out for how many years Arun needs to invest ₹4,000 at 2% simple interest per annum to double his sum, we can use the formula for simple interest:

Simple Interest (SI) = (Principal × Rate × Time) / 100

To double his investment, the final amount should be ₹8,000. Hence, the simple interest earned should be ₹8,000 - ₹4,000 = ₹4,000.

Plugging the known values into the formula:
4,000 = (4,000 × 2 × Time) / 100

Solving for Time:

4,000 × 100 = 4,000 × 2 × Time

400,000 = 8,000 × Time

Time = 400,000 / 8,000

Time = 50

So, Arun needs to invest the amount for 50 years to double his sum at a 2% simple interest rate per annum. Thus, the correct answer is 50 years.