Question

Dolly has a cumulative time deposit account in a bank. She deposits ₹ 600 per month for 6 years. If at the end of maturity period she gets ₹ 55026, find the rate of interest.

Answer 1

Given:

Monthly deposit, P = ₹ 600

Time, n = 6 years = 72 months

Maturity value (MV) = ₹ 55026

Total amount deposited

600 × 72

= ₹ 43200

Interest earned

Interest = 55026 − 43200

= ₹ 11826

Use interest formula

Interest (I) = `(Pxxn(n+1)xxr)/(2xx12xx100)`

`11826 = (600xx72xx73xxr)/(2xx12xx100)`

`= (600xx6256xxr)/2400`

`= (3153600xxr)/2400`

`11826 = (3153600 r)/2400`

`=> r = (11826xx2400)/3153600`

= 9%