A sum of money becomes ₹5100 after 3 years and ₹5950 after 4 years on compound interest. The rate of interest per annum is:
Answer & explanation
Correct answer: option 4
The correct answer is Option (4) → 50/3%
Given:
- Amount after 3 years: $A_3 = ₹5100$
- Amount after 4 years: $A_4 = ₹5950$
- Let rate = $r\% = \frac{r}{100}$ per annum
- Let principal = P
Step 1: Relation between consecutive years
$A_4 = A_3 \cdot (1 + r/100)$
$5950 = 5100 \cdot (1 + r/100)$
$1 + r/100 = \frac{5950}{5100} = \frac{595}{510} = \frac{119}{102} \approx 1.1667$
Step 2: Solve for r
$1 + r/100 = 1.1667$
$r/100 = 0.1667$
$r = 16.67\% = \frac{50}{3}\%$