At what rate per cent of compound interest will a sum of Rs. 2,000 amount to Rs. 4,394 in 3 years?

Correct option is C

Given:

Principal (P) = Rs. 2,000

Amount (A) = Rs. 4,394

Time (T) = 3 years

Formula Used:

​$$A = P \left(1 + \frac{R}{100}\right)^T$$​​

Solution:​

Using the formula;

​$$4394 = 2000 \left(1 + \frac{R}{100}\right)^3$$​​

​$$\left(1 + \frac{R}{100}\right)^3 = \frac{4394}{2000}$$​​

​$$1 + \frac{R}{100} = \sqrt[3]{\frac{2197}{1000}}$$​​

​$$\frac{R}{100} = \frac{13}{10}-1$$​​

​$$\frac{R}{100} = \frac{3}{10}$$​​

R = 30%

Thus, The rate of compound interest is 30% per annum