Question

Each of A and B both opened a recurring deposit accounts in a bank. If A deposited Rs. 1,200 per month for 3 years and B deposited Rs. 1,500 per month for 2 ½ years; find, on maturity, who will get more amount and by how much? The rate of interest paid by the bank is 10% per annum.

Answer 1

For A

Installment per month (P) = Rs. 1,200

Number of months (n) = 36

Rate of interest (r) = 10% p.a.

∴ `S.I. = P xx (n(n + 1))/(2 xx 12) xx r/100` 

= `1200 xx (36(36 + 1))/(2 xx 12) xx 10/100`

= `1200 xx 1332/24 xx 10/100`

= Rs. 6,660

The amount that A will get at the time of maturity

= Rs. (1,200 × 36) + Rs. 6,660

= Rs. 43,200 + Rs. 6,660

= Rs. 49,860

For B

Instalment per month (P) = Rs. 1,500

Number of months (n) = 30

Rate of interest (r) = 10% p.a.

∴ `S.I. = P xx (n(n + 1))/(2 xx 12)  xx r/100`

= `1500 xx (30(30 + 1))/(2 xx 12) xx 10/100`

= `1500 xx 930/24 xx 10/100`

= Rs. 5,812.50

The amount that B will get at the time of maturity

= Rs. (1,500 × 30) + Rs. 5,812.50

= Rs. 45,000 + Rs. 5,812.50

= Rs. 50,812.50

Difference between both amounts = Rs. 50,812.50 – Rs. 49,860

= Rs. 952.50

Then B will get more money than A by Rs. 952.50