In a recurring deposit account for 2 years, the total amount deposited by a person is ₹ 9600. If the interest earned by him is one-twelfth of his total deposit, then find :

(a) the interest he earns

(b) his monthly deposit

(c) the rate of interest

(a) Given,

Interest earned by man = One-twelfth of the total deposit

= $\dfrac{1}{12} \times 9600$

= ₹ 800.

Hence, the interest earned = ₹ 800.

(b) Given,

In a recurring deposit account for 2 years (or 24 months), the total amount deposited by a person is ₹ 9600.

Money deposited per month = $\dfrac{9600}{24}$ = ₹ 400.

Hence, monthly deposit = ₹ 400.

(c) By formula,

Rate of interest = $\dfrac{\text{Interest earned}}{\text{Amount invested}} \times 100\%$

$= \dfrac{800}{9600} \times 100\% = \dfrac{100}{12} = 8\dfrac{1}{3}$ %.

Hence, rate of interest = $8\dfrac{1}{3}$ %.