Question

Seep has a $4$ year recurring deposit account in a bank and deposits Rs $1800$ per month. If she gets Rs $1,08,450$ at the time of maturity , find rate of interest.

• A. $12.5$ $\%$
• B. $14$ $\%$
• C. $18$ $\%$
• D. None of the above

Answer 1

The correct option is A $12.5$ $\%$

Given, maturity amount $=1,08,450$, $n=4\times 12=48$, monthly installment Rs. $=1800$

We need to find rate of interest i.e. $r$

Interest $=\frac{Pn(n+1)r}{2400}$

$=\frac{1800\times 48\times 49\times r}{2400}$

$=764r$

Therefore, amount $=(Pn+1764r)$

$\Rightarrow 1,08,450=(1800\times 48+1764r)$

$\Rightarrow 1,08,450=86400+1764r$

$\Rightarrow 1764r=22050$

$\Rightarrow r=12.5\%$