## Quantitative Aptitude Questions and Answers - Compound Interest

11. Suresh borrows Rs.6375 to be paid back with compound interest at the rate of 4 % pa by the end of 2
year in two equal yearly installments. How much will each installment will be?

A. 3840

B. 3380

C. 4800

D. Data inadequate

View Answer

Ans : B

Explanation: 25x/26 + 625/676x = 6375

x = (6375 * 676)/1275 = 3380

12. If Rs. 7200 amounts to Rs.10368 at compound interest in a certain time , then Rs. 7200 amounts to what
in half of the time?

A. Rs 6570

B. Rs 7850

C. Rs 8140

D. Rs 8640

View Answer

Ans : D

Explanation: Let rate = R% and time = n year

Then, 10368 =7200(1+R/100)n

⇒ (1+R/100)n = 10368/7200 = 1.44

∴ (1 + R/100)n/2 = √1.44 = 1.2

∴ Required amount for n/2 yr

= 7200(1+ R/100)n/2

= 7200 x 1.2 = Rs. 8640

13. Find the compound interest on Rs. 64,000 for 1 year at the rate of 10% per annum compounded quarterly
(to the nearest integer).

A. Rs. 8215

B. Rs. 8205

C. Can’t be determined

D. None of the above

View Answer

Ans : D

Explanation: 64000*(1.025)^4=70644.025

Ci=6644.025

14. On a certain rate of interest a sum of Rs 5000 becomes Rs 16,200 in certain years at compound interest.
In half of the time given, this sum will become?

A. 9000

B. 10000

C. 8000

D. 7000

View Answer

Ans : A

Explanation: a--------b-----c

5000------ X ----16200

----t------- t ----

As we have to calculate the sum for half time, both time period is same, and hence

a:b = b:c

5000:x = x:16200

x=Rs 9000

15. If a sum of RS 2744000 becomes Rs 3176523 in three years on Compound Interest then find the rate of
interest.

A. 0.1

B. 0.08

C. 0.11

D. 0.05

View Answer

Ans : D

Explanation: Find the cube root of both numbers. Cube root-> 3 years

cube root(2744000): cube root(3176523)

140:147

rate=(147-140)/140*100=5

16. What is the difference between Simple Interest and Compound Interest on Rs 70,000 ar 20% rate of
interest in one and a half year if Compound Interest is compounded half yearly.

A. Rs 2070

B. Rs 2160

C. Rs 2170

D. Rs 2060

View Answer

Ans : C

Explanation: SI on 1 (1/2) year= 20*1.5=30%

SI on 1 (1/2) years of compounded half yearly make rate half yearly and time double

r=10%=1/10 ; t=3 years

r=331/1000*100=33.1

33.1%of 70,000 = 2170

17. A sum of money is lent for 2 years at 20% p.a. compound interest. It yields Rs 482 more when
compounded semi-annually than compounded annually. What is the sum lent?

A. Rs 25,600

B. Rs 20,000

C. Rs 26,040

D. Rs 40,500

View Answer

Ans : B

Explanation: P[1 + (r/2)/100]4 – P[1 + r/100]2 = 482

P[1 + 10/100]4 – P[1 + 20/100]2 = 482

Solve, P = 20,000

18. Rs 3903 is to be divided in a way that A share at the end of 7 years is equal to the B share at the end
of 9 years. If the rate of interest is 4% compounded annually, find A share.

A. 1875

B. 1975

C. 1525

D. 1675

View Answer

Ans : A

Explanation: A's share = (1 + 4/100)^7

B's share = (1 + 4/100)^9

Divide both, B/A = (1 + 4/100)2 = 676/625

So A's share = 625* 3903/(676+625) =1875

19. What will Rs.1500 amount to in three years if it is invested in 20% p.a. compound interest, interest being
compounded annually?

A. 2145

B. 2358

C. 2450

D. 2592

View Answer

Ans : D

Explanation: 20%1500=300

20%300=60=>300+60=360

20%360=72=>360+72=432

Ci=432+360+300=1092

A=1500+1092=2592

20. Rs.100 doubled in 5 years when compounded annually. How many more years will it take to get another
Rs.200 compound interest?

A. 10 yrs

B. 8 yrs

C. 7 yrs

D. 5 yrs

View Answer

Ans : D

Explanation: Rs.100 invested in compound interest becomes Rs.200 in 5 years.

The amount will double again in another 5 years.

=>the amount will become Rs.400 in another 5 years.

So, to earn another Rs.200 interest, it will take another 5 years.

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