A sum of money becomes ₹5100 after 3 years and ₹5950 after 4 years on compound interest. The rate of interest per annum is:

50/3%

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

$1 + r/100 = 1.1667$

$r/100 = 0.1667$

$r = 16.67\% = \frac{50}{3}\%$