Simple Interest - Quantitative Aptitude (MCQ) questions

1)   A sum becomes Rs. 3000 at the rate of 12% per annum (simple interest). The same sum becomes Rs. 3300 at the rate of 15% per annum (simple interest) in the same duration. Find the sum and the duration.
- Published on 17 Mar 17

a. Rs. 2000 and 20 years
b. Rs. 1900 and 8.25 years
c. Rs. 1500 and 7 years
d. Rs. 1800 and 5.5 years
Answer  Explanation 

ANSWER: Rs. 1800 and 5.5 years

Explanation:
simple interest


2)   An amount becomes 7 times in 15 years. In how many years will the same amount become 10 times? The rate of interest remains the same for both cases.
- Published on 15 Mar 17

a. 20 years
b. 18.75 years
c. 22.50 years
d. 21.50 years
Answer  Explanation 

ANSWER: 22.50 years

Explanation:
simple interest


3)   In 40 years an amount becomes 6 times the original amount. What is the rate of interest?
- Published on 15 Mar 17

a. 12.5%
b. 24%
c. 6.67%
d. 34%
Answer  Explanation 

ANSWER: 12.5%

Explanation:
simple interest


4)   A TV can be bought for Rs. 20000 cash or by paying in four equal monthly installments with an initial down payment of Rs. 4000. If the rate of interest for this facility is 8% per annum, then what would be the installment charged for each month?
- Published on 15 Mar 17

a. Rs. 4000
b. Rs. 4106.67
c. Rs. 4050.33
d. Rs. 4066.01
Answer  Explanation 

ANSWER: Rs. 4066.01

Explanation:
simple interest
simple interest


5)   How much should be the annual installment to completely pay off a debt of Rs. 1078 in 6 years at 9% per annum rate of interest?
- Published on 10 Mar 17

a. Rs.146.35
b. Rs.156.25
c. Rs.126.55
d. Rs.118.35
Answer  Explanation 

ANSWER: Rs.146.35

Explanation:
First take Installment amount = P = Rs. 100

Total installments = 6 (One installment per year)

Simple and Easy rule -
If there are ‘n’ installments, then, 1st installment will have interest for (n-1) years, 2nd will have interest for (n-2) years and so on.

So in this case, n=6
1st installment will have interest for 5 years (n-1 = 6-1=5 years)
2nd installment will have interest for 4 years (n-2 = 6-2=4 years)
3rd installment will have interest for 3 years (n-3 = 6-3= 3 years)
4th installment will have interest for 2 years (n-4 = 6-4= 2 years)
5th installment will have interest for 1 year (n-5 = 6-5= 1 year)
6th installment will have no interest (n-6 = 6-6= 0 years)

Total Amount = 6 Installments + Interest on those 6 Installments
simple interest
Now here, rate of interest is same for all installments = R = 9%

P = Rs. 100 (same amount Rs. 100 for all installments)

From above rule we can calculate effective time period ‘T’

T (for interest calculation) = 5 years + 4 years + years + 2 years + 1 year + 0 years

simple interest


6)   An amount of Rs. 6500, at simple quarterly interest of 8%, will yield how much in 2 and half years?
- Published on 10 Mar 17

a. Rs. 6300
b. Rs. 7050
c. Rs. 6600
d. Rs. 7800
Answer  Explanation 

ANSWER: Rs. 7800

Explanation:
simple interest


7)   Rs. 20400 was divided in two parts and then invested. One part invested at 6.25% for 8 years yields the same interest as the other part invested at 7% for 5 years. What is the value of smaller part?
- Published on 10 Mar 17

a. 9600
b. 8400
c. 10100
d. 6500
Answer  Explanation 

ANSWER: 8400

Explanation:
simple interest


8)   1/5 part of an amount was given at 3% simple interest, 1/3 part was given at 5% simple interest, 2/5 parts at 9% simple interest and remaining part at 11% simple interest. The total interest received was Rs.297. How much amount was originally given?
- Published on 10 Mar 17

a. 4500
b. 5500
c. 3950
d. 4200
Answer  Explanation 

ANSWER: 4500

Explanation:
simple interest


9)   A man got Rs. 130 less, as simple interest, when he invested Rs. 2000 for 4 years as compared to investing Rs. 2250 for same duration. What is the rate of interest?
- Published on 05 Mar 17

a. 12%
b. 13%
c. 12.5%
d. 10.50%
Answer  Explanation 

ANSWER: 13%

Explanation:
simple


10)   Find the principal which yields a simple interest of Rs. 20 and compound interest of Rs. 21 in two years, at the same percent rate per annum?
- Published on 06 May 16

a. Rs. 520
b. Rs. 480
c. Rs. 420
d. Rs. 200
Answer  Explanation 

ANSWER: Rs. 200

Explanation:
SI in 2 years = Rs. 20, SI in 1 year = Rs. 10
CI in 2 years = Rs. 21
% rate per annum = [(CI – SI) / (SI in 1 year)] *100
= [(21 – 20) / 20] * 100
= 5 % p.a.

Let the principal be Rs. X
Time = T = 2 years
% rate = 5% p.a.
SI = (PRT/100)
20 = (X*5*2) / 100
X = Rs. 200


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