Question

A recurring deposit account of Rs.1,200 per month has maturity value of Rs.12,440. If the rate of interest is 3% and the interest is calculated at the end of every month ; find the time of this recurring deposit account.​

Answer 1

Answer:

Installment(P) per month = Rs 1200

number of months = n

let rate of interest = 8% per annum

SI=

2×12×100

P×n(n+1)×r

=

2×12×100

1200×n(n+1)×8

=4n(n+1)

Maturity value =(1200×n)+4n(n+1)=1200n+4n

2

+4n

Given Maturity value = Rs 12440

Then,

12440=1200n+4n

2

+4n

4n

2

+1204n−12440=0

On solving the equation, we get n = 10 months and n = -311 months (not possible)

Therefore, number of months = 10