Simple Interest
Question 1 
A sum amounts to Rs 2506 at simple interest rate of 13.5% per annum after 4 years. Find the sum.
1624.25  
1621.27  
1624.27  
1627.27 
Discuss it
Question 1 Explanation:
Let the required sum be x. Then,
Simple interest = (x × 4 × 13.5/100) = Rs 27x/50.
Amount = (x + 27x/50) = Rs 77x/50.
Therefore, 77x/50 = 2506
⇒ 77x = 2506 × 50
⇒ x = 125300/77
⇒ x = 1627.27.
Question 2 
Charles deposits a sum of Rs 800 that will amount to Rs 920 in 3 years. However, the bank decides to increase the interest rate by 4%. What amount will he receive now?
Rs 1015
 
Rs 1016
 
Rs 1025
 
Rs 1102

Discuss it
Question 2 Explanation:
Charles gets simple interest (SI) = Rs 920800 = Rs 120.
Here, Principal (P) = Rs 800 and Time (T) = 3 years.
We know, Rate (R) = (100×SI)/(P×T) = (100×120)/(800×3) = 5%.
Given, New Rate = 9%.
So, New Interest = P×R×T = 800×0.09×3 = Rs 216.
Therefore, Charles will get Rs (800+216) = Rs 1016.
Question 3 
What will be the simple interest on Rs 70,000 at 50/3 % per annum after 9 months?
Rs 8750  
Rs 8745  
Rs 8678  
Rs 8555 
Discuss it
Question 3 Explanation:
Given, Principal (P) = Rs 70000, Rate (R) = 50/3 % per annum and Time (T) = 9/12 = 3/4 years.
Simple Interest (SI) = P×R×T = 70000×(50/300)×(3/4) = Rs 8750.
Question 4 
George invests an amount of Rs 15800 for 9 months at the rate of 25/4 % per annum. Find out of the simple interest on his investment.
Rs 740  
Rs 745.63  
Rs 742.63  
Rs 740.63 
Discuss it
Question 4 Explanation:
Given,
Principal = 15800.
Rate = 25/4 % per annum.
Time = 9/12 = 3/4 years.
Hence, SI = 15800×(25/400)×(9/12) = Rs 740.63.
Question 5 
An amount of Rs.9600 lent out at a rate of 9/2 % per annum for a 1 year and 9 months. At the end of the period, the amount he earned as S.I was:
667  
756  
765  
625 
Discuss it
Question 5 Explanation:
Given that, principal = P = Rs.9600, R = 9/2 % and T = 1 year and 9 months = 1 + 9/12 year = 7/4 years.
Now, we have to find the S.I for 7/4 years.
S.I = PRT/100 = Rs. 9600 x 9/2 x 7/4 x 1/100 = 12 x 9 x 7 = 756
Hence, the required S.I amount is Rs.756
Now, we have to find the S.I for 7/4 years.
S.I = PRT/100 = Rs. 9600 x 9/2 x 7/4 x 1/100 = 12 x 9 x 7 = 756
Hence, the required S.I amount is Rs.756
Question 6 
Ram landed Rs.33600 at 25/4 % per annum for 9 months. Find the amount he received as S.I.
1565  
1522  
1675  
1575 
Discuss it
Question 6 Explanation:
S.I = PRT/100
= Rs. 33600 x 25/4 x 3/4 x 1/100 = 21 x 25 x 3
= Rs.1575.
= Rs. 33600 x 25/4 x 3/4 x 1/100 = 21 x 25 x 3
= Rs.1575.
Question 7 
Ram has an amount of Rs. 9000. How much time will it take to earn 1620 as S.I at a rate of 4.5% per annum?
2  
1  
5  
4 
Discuss it
Question 7 Explanation:
SI = PRT/100
T = S.I x 100/PR = 1620 x 100/9000 x 4.5
= 4
Question 8 
At what rate of SI, a sum of Rs.7000 amounts to Rs.7700 in 2 years?
5.5%  
6.5%  
6%  
5% 
Discuss it
Question 8 Explanation:
SI= 77007000 = 700
700 = 7000*R*2/100
R = 70000/14000 = 5%
Question 9 
Find the simple interest on Rs.300 for 6 months at 10% per annum.
20  
15  
17  
13 
Discuss it
Question 9 Explanation:
SI = 300*10*(6/12)/100
= 15
= 15
Question 10 
A sum of Rs.468.75 was lent out at simple interest and at the end of 1 2/3 year the SI earned is Rs 31.25. Find the rate of interest per cent annum.
5  
4  
4.25  
6 
Discuss it
Question 10 Explanation:
R=SI. 100/P.T
= (31.25 X 100)/(468.75 X 5/3)
= 4
Question 11 
In what time will Rs.8500 pay an amount of Rs. 7267.50 as S.I at 4.5 per cent per annum?
19  
20  
18  
21 
Discuss it
Question 11 Explanation:
SI=PRT/100
T= SI X 100/(P X R)
= 7267.50 X 100/(8500 X 4.5)
= 19 years
T= SI X 100/(P X R)
= 7267.50 X 100/(8500 X 4.5)
= 19 years
Question 12 
The SI on a sum is 1/4^{th} of the principal, and the duration(in years) is equal to the rate per cent per annum. Find the rate per cent.
5  
11/10  
10  
11 
Discuss it
Question 12 Explanation:
SI= PRT/100
R=SI X100/(P X T)
= (P/4)X100/PXR
R^{2} = 100/4
R=5
Question 13 
The rate of interest for the first 2 yrs is 3% per annum, for the next 3 years is 8% per annum and for the period beyond 5 years 10% per annum. A person deposited some money 6 years back. Now he earns an interest of RS. 1520. What money did he deposit?
3600  
5000  
3800  
4100 
Discuss it
Question 13 Explanation:
Say Deposited money is P.
1520 = P X 3 X 2/100 + P X 8 X 3/100 + P X 10 X 1/100
1520 = P . 40/100
P = 1520 X 100/ 40
P = 3800
1520 = P X 3 X 2/100 + P X 8 X 3/100 + P X 10 X 1/100
1520 = P . 40/100
P = 1520 X 100/ 40
P = 3800
Question 14 
A sum of money doubles itself in 10 years at simple interest. What is the rate of interest?
11  
15  
20  
10 
Discuss it
Question 14 Explanation:
SI = P
P = P X R X 10/100
R= 10 %
P = P X R X 10/100
R= 10 %
Question 15 
A certain amount was lent at a rate R for 2 yrs at SI. If it been put at 3% higher rate, it would have fetched Rs 300 more. Find the amount?
5500  
6000  
5000  
4500 
Discuss it
Question 15 Explanation:
SI = P X R X 2/100...........(1)
SI+300 = PX(R+3) X 2/100.....(2)
P=5000
SI+300 = PX(R+3) X 2/100.....(2)
P=5000
There are 15 questions to complete.