# Simple Interest Questions and Answers updated daily – Aptitude

15 Simple Interest Questions and answers section with explanation for various online exam preparation, various interviews, Aptitude Simple Interest online test. Simple Interest Questions with detailed description, explanation will help you to master the topic.

## Simple Interest Questions

1. In how many years Rs 150 will produce the same interest at 8% as Rs. 800 produce in 3 years at 9/2%

Correct Ans:9
Explanation:
Firstly we need to calculate the SI with prinical 800,Time 3 years and Rate 9/2%, it will be Rs. 108

Then we can get the Time as

Time = (100*108)/(150*8) = 9

2. A man took loan from a bank at the rate of 12% p.a. simple interest. After 3 years he had to pay Rs. 5400 interest only for the period. The principal amount borrowed by him was:

Correct Ans:15,000
Explanation:
Principal = Rs. 100 x 5400 / 12 x 3 = Rs. 15000.

3. An automobile financier claims to be lending money at simple interest, but he includes the interest every six months for calculating the principal. If he is charging an interest of 10%, the effective rate of interest becomes:

Correct Ans:10.25%
Explanation:
Let the sum be Rs. 100. Then,

S.I. for first 6 months = Rs.100 x 10 x 1 / 100 x 2= Rs. 5

S.I. for last 6 months = Rs.105 x 10 x 1 / 100 x 2= Rs. 5.25

So, amount at the end of 1 year = Rs. (100 + 5 + 5.25) = Rs. 110.25

Effective rate = (110.25 - 100) = 10.25%

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

Correct Ans:4 years
Explanation:
Time =100 x 81 / 450 x 4.5years= 4 years.

5. A sum of money amounts to Rs 9800 after 5 years and Rs 12005 after 8 years at the same rate of simple interest. The rate of interest per annum is

Correct Ans:12%
Explanation:
We can get SI of 3 years = 12005 - 9800 = 2205

SI for 5 years = (2205/3)*5 = 3675 [so that we can get principal amount after deducting SI]

Principal = 12005 - 3675 = 6125

So Rate = (100*3675)/(6125*5) = 12%

6. In how many years Rs 150 will produce the same interest at 8% as Rs. 800 produce in 3 years at 9/2%

Correct Ans:9
Explanation:
Firstly we need to calculate the SI with prinical 800,Time 3 years and Rate 9/2%, it will be Rs. 108

Then we can get the Time as

Time = (100*108)/(150*8) = 9

7. At what rate percent per annum will the simple interest on a sum of money be 2/5 of the amount in 10 years

Correct Ans:4%
Explanation:
Let sum = x
Time = 10 years.
S.I = 2x /5, [as per question]
Rate =( (100 * 2x) / (x*5*10))%
=> Rate = 4%

8. A sum of money at simple interest amounts to Rs. 2240 in 2 years and to Rs. 2600 in 5 years. What is the principal amount

Correct Ans:2000
Explanation:
SI for 3 year = 2600-2240 = 360
SI for 2 year 360/3 * 2 = 240
principal = 2240 - 240 = 2000

9. Reema took a loan of Rs 1200 with simple interest for as many years as the rate of interest. If she paid Rs. 432 as interest at the end of the loan period, what was the rate of interest.

Correct Ans:6%
Explanation:
Let rate = R% then Time = R years.
=>1200∗R∗R / 100=432=>R2=36=>R=6%

10. If a sum of money doubles itself in 8 years at simple interest, the ratepercent per annum is

Correct Ans:12.5
Explanation:
Let sum = x then Simple Interest = x

Rate = (100 * x) / (x * 8) = 12.5

11. At 5% per annum simple interest, Rahul borrowed Rs. 500. What amount will he pay to clear the debt after 4 years

Correct Ans:600
Explanation:
We need to calculate the total amount to be paid by him after 4 years, So it will be Principal + simple interest.

So,
=>500+500∗5∗4 / 100=>Rs.600

12. Find the rate at Simple interest, at which a sum becomes four times of itself in 15 years.

Correct Ans:20%
Explanation:
Let sum be x and rate be r%
then, (x*r*15)/100 = 3x [important to note here is that simple interest will be 3x not 4x, beause 3x+x = 4x]

=> r = 20%

13. Sahil took a loan for 6 years at the rate of 5% per annum on Simple Interest, If the total interest paid was Rs. 1230, the principal was

Correct Ans:4100
Explanation:
S.I.=P∗R∗T / 100=>P=S.I.∗100 / R∗T

By applying above formula we can easily solve this question, as we are already having the simple interest.

=>P=1230∗100 / 6∗5=>P=4100

14. Find the simple interest on the Rs. 2000 at 25/4% per annum for the period from 4th Feb 2005 to 18th April 2005

Correct Ans:25
Explanation:
One thing which is tricky in this question is to calculate the number of days.
Always remember that the day on which money is deposited is not counted while the day on which money is withdrawn is counted.
So lets calculate the number of days now,
Time = (24+31+18) days = 73/365 years = 1/5 years
P = 2000
R = 25/4%

S.I. = =2000×25 / 4×5×100=25

15. Find the simple interest on Rs 7000 at 50/3 % for 9 months