In an R.D., the maturity value is the sum of the total amount deposited and the interest. If P is the amount deposited every month for n months and R is the rate of interest, then interest I is equal to:

1. $P \times \dfrac{n}{12} \times \dfrac{R}{100}$

2. $P \times \dfrac{n(n - 1)}{12} \times \dfrac{R}{100}$

3. $P \times \dfrac{n(n + 1)}{2 \times 12} \times \dfrac{R}{100}$

4. $P \times \dfrac{n}{2 \times 12} \times \dfrac{R}{100}$

Mohit opened a Recurring deposit account in a bank for 2 years. He deposits ₹1,000 every month and receives ₹25,500 on maturity. The interest he earned in 2 years is:

1. ₹13,500

2. ₹3,000

3. ₹24,000

4. ₹1500

Mr. Anuj deposits ₹500 per month for 18 months in a recurring deposit account at a certain rate. If he earns ₹570 as interest at the time of maturity, then his matured amount is:

1. ₹(500 x 18 + 570)

2. ₹(500 x 19 + 570)

3. ₹(500 x 18 x 19 + 570)

4. ₹(500 x 9 x 19 + 570)

Anwesha intended to open a Recurring Deposit account of ₹ 1000 per month for 1 year in a Bank, paying a 5% per annum rate of simple interest. The bank reduced the rate to 4% per annum. How much must Anwesha deposit monthly for 1 year so that her interest remains the same?

1. ₹ 12325

2. ₹ 1250

3. ₹ 1200

4. ₹ 1000