Question

On a certain some of money, the rate of interest for the first 4 years is 6%, for the next two years it is 4% and 8% per annum for the period beyond 6 years. If the simple interest accrued by the sum of the total period of 10 years is Rs.1984. What is the sum?
1. Rs. 3100
2. Rs.5000
3. Rs. 4700
4. Rs. 7580

Answer 1

Correct Answer - Option 1 : Rs. 3100

Given∶

The rate of interest for the first 4 years is 6%,

The rate of interest for the next 2 years is 4%,

The rate of interest for the beyond 6 years is 8%

S.I. = Rs. 1984

Formula Used∶

S.I. = PRT/100

Calculation∶

Let the Principal be 'P' .

S.I. @6% 4 years, 

(P× 6× 4)/100 = 24 P/100

S.I. @4% for 2 years,

(P× 4 × 2)/100 = 8P/100

S.I.for the next 4 years,

(P × 8 × 4)/100 = 32P/100

Total S.I = 24/100 + 8P/100 + 32P/100

⇒ 64 P/100

But S.I. = 1984

⇒ 64 P/100 = 1984 

⇒ P = 3100

∴ The sum of money is of Rs 3100.