Question

A page from the saving bank account of Mrs. Ravi in the year $2006$ is given below:

Date	Particulars	Withdrawal (Rs)	Deposit (Rs)	Balance (Rs)
April $3^{rd}$	B/F	-	-	$6,000$
April $7^{th}$	By Cash	-	$2,300$	$8,300$
April ${15}^{th}$	By cheque	-	$3,500$	$11,800$
May ${20}^{th}$	To Self	$4,200$	-	$7,600$
June ${10}^{th}$	By cash	-	$5,800$	$13,400$
June ${15}^{th}$	To self	$3,100$	-	$10,300$
August ${13}^{th}$	By cheque	-	$1,000$	$11,300$
August ${25}^{th}$	To self	$7,400$	-	$3,900$
September $6^{th}$	By cash	-	$2,000$	$5,900$

She closed the account on ${30}^{th}$ September, $2006$. Calculate the interest Mrs. Ravi earned at the end of ${30}^{th}$ September, $2006$ at $4.5\%$ per annum interest. Hence find the amount she receives on closing the account.

Answer 1

For interest as per the entries of the passbook, we have

Month	Minimum balance between ${10}^{th}$ day and the last day (in Rs)
April	$8,300$
May	$7.600$
June	$10,300$
July	$10,300$
August	$3,900$
Total	$40,400$

Principal for $1$ months $(\text{i.e.},\frac{1}{12}\text{year})=$ Rs. $40,400$
Interest $=\frac{P\times R\times T}{100}$
$=\frac{40,400\times \frac{1}{12}\times 4.5}{100}$
$=$ Rs. $151.50$
The amount she receive on ${30}^{th}$ September, $2006=$ Last balance $+$ Interest
$=$ Rs. $5,900+$ Rs. $151.50$
$=$ Rs. $6051.50$