SSC GD 2023 PYQ — Question 49

SSC GD Constable (English) - 25 Jan 2023 - Shift 4 • Quantitative Aptitude • Q49

A sum of P was borrowed and paid back in three equal yearly instalments, each of ₹30,000. If the rate of interest was 5% compounded annually, then the value of P (approximate) is: 

Show answer & explanation

Correct answer: C

Explanation

The Correct answer is Option 3 i.e.₹81,697.

Formulae for each installment in case of compound interest

P = x/(1 + r/100) + x/(1 + r/100)2 +..... + x/(1 + r/100)n

x = each installment

Now, according to the question

⇒ P = 30000/(1 + 5/100) + 30000/(1 + 5/100)2 + 30000/(1 + 5/100)3

⇒ P = 30000/(21/20) + 30000/(21/20)2 + 30000/(21/20)3

⇒ P = 30000 × 20/21 + 30000 × 20/21 × 20/21 + 30000 × 20/21 × 20/21 × 20/21

⇒ P = 28571.42 + 27210.88 + 25915.12

⇒ P = 81697.42 or

⇒ P = Rs.81697