10. Mr. Bhardwaj has a recurring deposit account with Punjab National Bank for 3 years. If the rate of
interest is 8% p.a. and Mr. Bharadwaj gets 101100 as maturity amount, find the sum he has been
depositing every month.
Answers
[tex]It is given that,
Amount deposited per month (P) = ₹ 600,
Rate of interest = 7% p.a.
Amount of maturity = ₹ 15,450.
Consider n months as the period,
We know that
Total principal for one month = 600∗n(n+1)/2
By further calculation,
= 600(n2+n)/2
= 300(n2/n)
Here interest = PRT/100,
Substituting the values
= (300(n2+1)∗7∗1)/(100/12)
= 7/4(n2+n)
Amount of maturity = 600n+7/4(n2+n),
Substituting the values
600n+7/4(n2+n)=15450
By further calculation
2400+7n2+7n=61800
7n2+2407n−61800=0
We can write it as,
7n2−168n+2575n−61800=0
7n(n−24)+2575(n−24)=0
(n−24)(7n+2575)=0
Here, n−24=0 where n=24
Similarly
7n+2575=0
Where 7n=−2575
n=−2575/7 which is not possible as it is negative.
Period (n) = 24 months or 2 years.
n = 3 years = 3×12 months =36 mts
r = 8 pa
P = ?
MV = ₹101100
Use this formula to find the next part
MV = Pn(n+1)r/24×100