Question

(1) Find the maturity amount
b) Mr Rao has a cumulative deposit account for 3 years at 7% interest p.a. She receives 7,977 as
the maturity amount after three years.
(1) Find the monthly deposit.
(ii) Find the total interest receivable after maturity
of 30 ner month at 8% simple interest per​

Answer 1

Correct question!

Mr Rao has a cumulative deposit account for 3 years at 7% interest p.a. He receives 7977 as the maturity amount after 3 years.

(1) Find his monthly deposit.

(2) Find the interest after 30 months at the rate of 8% p.a with the same principal.

Solution!!

The concept of commercial mathematics has to be used here.

(1)

Principal = x

Rate of interest = 7%

Time = 3 years = 36 months

MV = Rs 7977

MV = $\sf P\times n+P\times \dfrac{(n+1)n\times R}{2\times 12\times 100}$

7977 = 36x + x × (37 × 36 × 7)/(12 × 2 × 100)

7977 = 36x + 3.885x

7977 = 39.885x

x = 7977 ÷ 39.885

x = 200

Hence, monthly deposit is Rs 200.

(2)

Principal = Rs 200

Rate of interest = 8%

Time = 30 months

Interest = ((n + 1)n × R)/(2 × 12 × 100)

Interest = (31 × 30 × 8)/(2 × 12 × 100)

Interest = Rs 3.1