Simple Interest

Question 1

A sum amounts to Rs 1065 at simple interest rate of 7.5% per annum after 3 years. Find the sum.

• A. 878.40
• B. 869.38
• C. 869.28
• D. 783.20

Answer: (B)

Let the required sum be x. Then, 

Simple interest = (x × 3 × 7.5 /100) = Rs 22.5x/100. 

Amount = (x + 22.5x/100) = Rs 122.5x/100. 

Therefore, 122.5x/100 = 1065 ⇒ 122.5x = 1065 × 100 ⇒ x = 106500/122.5 ⇒ x = 869.38

Question 2

James 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?

• A. Rs 1015
• B. Rs 1016
• C. Rs 1025
• D. Rs 1102

Answer: (B)

James gets simple interest (SI) = Rs 920-800 = 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, James 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?

• A. Rs 8750
• B. Rs 8745
• C. Rs 8678
• D. Rs 8555

Answer: (A)

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

Find out the simple interest if Harry invests an amount of Rs 15800 for 9 months at the rate of 25/4 % per annum. 

• A. Rs 740.54
• B. Rs 745.63
• C. Rs 742.63
• D. Rs 740.63

Answer: (D)

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

After lending out an amount of Rs.9600 at a rate of 9/2 % per annum for a 1 year and 9 months, what was the S.I earned ? 

• A. 677
• B. 756
• C. 765
• D. 625

Answer: (B)

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

Question 6

Find the amount of S.I received by Ram after getting Rs.3360 at 25/4 % per annum for 9 months.

• A. 156.5
• B. 153.2
• C. 168.5
• D. 157.5

Answer: (D)

S.I = PRT/100 
= Rs. 3360 x 25/4 x 3/4 x 1/100 = 21 x 25 x 3 
= Rs.157.5

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?

• A. 2
• B. 1
• C. 5
• D. 4

Answer: (D)

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?

• A. 5.5%
• B. 6.5%
• C. 6%
• D. 5%

Answer: (D)

SI= 7700-7000 = 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.

• A. 20
• B. 15
• C. 17
• D. 13

Answer: (B)

SI = 300*10*(6/12)/100
= 15

Question 10

• A. 5
• B. 4
• C. 4.25
• D. 6

Answer: (B)

R=SI. 100/P.T = (31.25 X 100)/(468.75 X 5/3) = 4