A sum invested at a certain rate of interest per annum compounded annually amounts to Rs14 400 in 2 ...........

Quantitative Aptitude (MTS) Compound Interest

A sum invested at a certain rate of interest per annum, compounded annually, amounts to Rs14,400 in 2 years and to Rs25,920

in 4 years. What is the sum invested?

This questions was previously asked in

SSC MTS 21st July 2022 Shift-1

Rs8,200

Rs7,500

Rs8,500

Rs8,000

- We need to determine the original sum (`P`) when interest is compounded annually.

- Given: Amount after 2 years is Rs14,400. After 4 years, it is Rs25,920.

- The amount relation with principal and rate (R) after n years is: \( A = P \cdot (1 + \frac{R}{100})^n \).

- By dividing the two equations:

\( \frac{25,920}{14,400} = (1 + \frac{R}{100})^2 \).

- This gives us \( (1 + \frac{R}{100})^2 = 1.8 \), so \( 1 + \frac{R}{100} = \sqrt{1.8} \).

- Finding amount relation after the first period gives:

\( 14,400 = P \cdot 1.2^2 \).

- Solving gives original sum: Rs8,000.

- Thus, the correct option is:

Option 4: Rs8,000

Submit Error