# Simple Interest

Simple Interest - Important Points

1. | At what rate percent of simple interest per annum will a sum of money double in 8 years. |
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A. 12.5%

B. 13.5%

C. 11.5%

D. 14.5%

View Answer Discuss Work SpaceAnswer: option a

Explanation:

Let principal = P, Then, SI = P after 8 years

We know that SI = PTR/100 = P

Rate = [(100 x P)/ (P x 8)]% = 12.5% per annum

2. | How much time will take for an amount of Rs. 450 to yield Rs. 81 as interest at 4.5% per annum of simple interest ? |
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A. 4 years

B. 2.5 years

C. 3.5 years

D. 2 years

View Answer Discuss Work SpaceAnswer: option a

Explanation:

**SI = PTR/100**

Time = (100 x 81) / (450 x 4.5) = 4 years

3. | A sum was put at simple interest at a certain rate for 3 years. Had it been put at 2% higher rate, it would have fetched Rs 360 more. Find the sum. |
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A. Rs.4000

B. Rs.9000

C. Rs.5000

D. Rs.6000

View Answer Discuss Work SpaceAnswer: option d

Explanation:

Let sum = P and original rate of interest = R

Then, [(P * (R+2) * 3)/100] - [ (P * R * 3)/100] = 360

=> 3P*(R+2) - 3PR = 36000

=> 3PR + 6P - 3PR = 36000

=> 6P = 36000

=> P = 6000

4. | A certain sum earns simple interest of Rs. 1750 in 7 years. Had the interest been 2% more, how much more interest would it have earned? |
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A. Rs.35

B. Rs.245

C. Rs.350

D. cannot be determined

View Answer Discuss Work SpaceAnswer: option d

Explanation:

We need to know the S.I, principal and time to find the rate. Since the principal is not given, so data is inadequate.

5. | The difference between the simple interest received from two different sources on Rs. 3000 for 3 years is Rs. 27. The difference between their rates of interest is: |
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A. 0.1%

B. 0.2%

C. 0.3%

D. 0.4%

View Answer Discuss Work SpaceAnswer: option c

Explanation:

=> [3000 x (R1-R2) x 3]/100 = 27

=> 9000 x (R1-R2) = 2700

=> (R1-R2)= 2700/9000 = 0.3 %