SSC GD 2024 PYQ — Question 49

SSC GD Const (English) - 22 Feb 2024 - Shift 4 • Quantitative Aptitude • Q49

Compound interest (compounding annually) on a sum for 2 years is Rs. 967.5. If rate of interest is 15 percent per annum, then what is the sum?

Show answer & explanation

Correct answer: A

Explanation

The correct answer is option 1 i.e. Rs. 3000.

A = P(1+r100)tP \left(1 + \frac{r}{100}\right)^t

( A) is the amount (Principal + Interest)

( P ) is the principal sum 

( r) is the rate of interest per annum = 15%

( t) is the time in years = 2 years

Compound Interest for 2 years = Rs. 967.5

⇒ A = P + (Compound Interest) = P + 967.5

⇒ P + 967.5 = P(1+15100)2P \left(1 + \frac{15}{100}\right)^2

⇒ P + 967.5 = P(1+0.15)2=P×1.152P \left(1 + 0.15\right)^2 = P \times 1.15^2

⇒ P + 967.5 = P × 1.3225

⇒ 967.5 = P × 1.3225 - P

⇒ 967.5 = P(1.3225 - 1)

⇒ 967.5 = P × 0.3225

⇒ P = 967.5 / 0.3225 = 3000

The sum (principal) is Rs. 3000.