Question

8. What sum of money invested at 7.5% p.a. simple interest for 2 years produces twice as much interest as 9600 in 3 years 6 months at 10% p.a. simple interest?


[Hint. Let the money invested be P]​

Answer 1

Answer:

First Case:

Principal (P1) = Rs 9600

Rate (R1) = 10%

Period = (T) = 3 years 6 months

= 3

2

1

years = 7 / 2 years

Simple interest = (P × R × T) / 100

= (9600 × 10 × 7) / (100 × 2)

We get,

= Rs 3360

Second case:

Simple interest = Rs 3360 × 2

= Rs 6720

Rate (R) = 7.5% p.a. and

Period (T) = 2 years

Therefore,

Principal = (S.I × 100) / (R × T)

= (6720 × 100) / (7.5 × 2)

= Rs (6720 × 100 × 10) / (75 × 2)

= 6720000 / 150

We get,

= Rs 44800