Govinda opened a R.D. account in a bank for 2 years 4 months. If the rate of interest is 8 % per year and the bank pays him ₹ 7,369.60 on maturity, find how much per month did Govinda deposit ?

Let Govinda deposited ₹ P per month.

Given,

Rate = 8%

Time = 2 years 4 months = 28 months

By formula,

⇒ M.V. = P × n + Interest

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

Substituting values we get :

$\Rightarrow 7369.60 = P \times 28 + P \times \dfrac{28 \times 29}{2 \times 12} \times \dfrac{8}{100} \\[1em] \Rightarrow 7369.60 = 28P + P \times \dfrac{7 \times 29}{3} \times \dfrac{1}{25} \\[1em] \Rightarrow 7369.60 = 28P + \dfrac{203P}{75} \\[1em] \Rightarrow 7369.60 = 28P + 2.70P \\[1em] \Rightarrow 7369.60 = 30.70 P \\[1em] \Rightarrow P = \dfrac{7369.60}{30.70} = ₹ 240.$

Hence, Govinda deposited ₹ 240 per month.