SSC GD 2024 PYQ — Question 50

The correct answer is option 1 i.e. 12.5 percent.

SI = ${P \times R \times T} \over 100$

Amount = P + SI

Let the sum of money be Rs. x.

According to the given question,

${x \times R \times 2} \over 100$ = 900 - x

⇒ R = ${(900 - x) \times 100}\over 2x$  ...(i)

Also, ${x \times R \times 4} \over 100$ = 1080 - x

⇒ R = ${(1080 - x) \times 100}\over 4x$   ..(ii)

Equating equations (i) and (ii),

⇒ ${(900 - x) \times 100}\over 2x$ = ${(1080 - x) \times 100}\over 4x$

⇒ 2(900 - x) = 1080 - x

⇒ 1800 - 2x = 1080 - x

⇒ x = 720

Putting this value in equation (i),

⇒ R = ${(900 - 720) \times 100}\over 2(720)$

⇒ R = 18000/1440

⇒ R = 12.5%

Hence the annual rate of interest is 12.5%.