Mr. Sam has a recurring deposit account and deposits ₹ 600 per month for 2 years. If he gets ₹ 15,600 at the time of maturity, find the rate of interest earned…

Let rate of interest be r%.

Given,

P = ₹ 600/month

n = 2 years or 24 months

M.V. = ₹ 15,600

By formula,

M.V = $P \times n + P \times \frac{n(n + 1)}{2 \times 12} \times \frac{r}{100}$

Substituting values we get :

$\Rightarrow 15600 = 600 \times 24 + 600 \times \frac{24(24 + 1)}{2 \times 12} \times \frac{r}{100}$

⇒ 15600 = 14400 + 6 × 25 × r

⇒ 15600 − 14400 = 6 × 25 × r

⇒ 150r = 1200

⇒ r = $\frac{1200}{150}$ = 8%.

Hence, rate of interest = 8%.