Question

Mr. Britto deposits a certain sum of money each month in a Recurring Deposit Account of a bank. If the rate of interest is of $8\%$ per annum and Mr. Britto gets Rs. $8088$ from the bank after $3$ years, find the value of his monthly instalment.

Answer 1

Let the monthly instalment be Rs. $x$
Given: Maturity amount=Rs. $8,088$, Time $\left(n\right)=3$ years$=3\times 12$ months $=36$ months, Rate $\left(R\right)=8\%$ p.a.
Principle for one month$=P\times \frac{n(n+1)}{2}$
$=\frac{x\times 36\times 37}{2}$
$=18\times 37x$
Interest $=\frac{18\times 37x\times 8\times 1}{100\times 12}$ $[\because I=\frac{PRT}{100}]$
$=\frac{444x}{100}$
Actual sum deposited $=36$x
Maturity amount $=$ Interest $+$ Actual sum deposited
$8,088=\frac{444x}{100}+36x$
$8,088=\frac{4,044x}{100}$
$\therefore x=\frac{8,088\times 100}{4,044}=200$
Hence, the monthly instalment be Rs. $200$.