Question

In how much time would Rs 5000 amount to Rs 6655 at 10% per annum compound interest?

Answer 1

Let the time period be n years. 
Thus, we have: 
\[\text{ CI = P }\left( 1 + \frac{R}{100} \right)^n - P\]
\[6, 655 = 5, 000 \left( 1 + \frac{10}{100} \right)^n - 5, 000\]
\[11, 655 = 5, 000 \left( 1 . 10 \right)^n \]
\[ \left( 1 . 1 \right)^n = \frac{11, 655}{5, 000}\]
\[ \left( 1 . 1 \right)^n = 2 . 331\]
\[ \left( 1 . 1 \right)^n = \left( 1 . 1 \right)^3 \]
On comparing both the sides, we get: 
n = 3
Thus, the required time is three years.