Sonia had a recurring deposit account in a bank and deposited ₹600 per month

Sonia had a recurring deposit account in a bank and deposited ₹600 per month for 2½ years. If the rate of interest was 10% p.a., find the maturity value of this account.

Answer

$$ \text{Qualifying Sum} = \frac {600 \times  30 \times (30 + 1)}{2} $$

$$ \text{Interest Rate} = \frac{ 600 \times 30 \times 31 \times 10}{2 \times 12 \times 100} = {₹2325} $$

$$ \text{M.V.} = {600 \times 30 + 2325} = {₹20325} $$