Assertion (A) : Mr. Sharma deposited ₹ 80 per month in a cumulative deposit account for 6 years at the rate of 6% p.a. Qualifying sum of his whole deposit = ₹ 6811.20

Reason (R) : Let a sum ₹ P be deposited every month in a bank for n months. If the rate of interest be r% p.a., then interest on the whole deposit (I) = $P \times \dfrac{n(n + 1)}{12} \times \dfrac{r}{100}$.

1. A is true, R is false.

2. A is false, R is true.

3. Both A and R are true.

4. Both A and R are false.

For a recurring deposit account in a bank, the deposit is ₹1,000 per month for 2 years at 10% p.a. rate of interest.

Statement (1): The interest earned is 10% of ₹(24 x 1,000).

Statement (2): For monthly instalment = ₹P, number of instalment = n and rate of interest r% p.a.; the interest earned = $\dfrac{P \times n \times (n + 1)}{12} \times \dfrac{r}{100}$.

1. Both statements are true.

2. Both statements are false.

3. Statement 1 is true, and statement 2 is false.

4. Statement 1 is false, and statement 2 is true.

Ritu has a Recurring Deposit Account in a bank and deposits ₹ 80 per month for 18 months. Find the rate of interest paid by the bank if the maturity value of this account is ₹ 1554.

The maturity value of a R.D. Account is ₹3,320. If the monthly instalment is ₹400 and the rate of interest is 10%; find the time (period) of this R.D. Account.