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

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

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%

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

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, 1^{st} installment will have interest for (n1) years, 2^{nd} will have interest for (n2) years and so on.
So in this case, n=6 1^{st} installment will have interest for 5 years (n1 = 61=5 years) 2^{nd} installment will have interest for 4 years (n2 = 62=4 years) 3^{rd} installment will have interest for 3 years (n3 = 63= 3 years) 4^{th} installment will have interest for 2 years (n4 = 64= 2 years) 5^{th} installment will have interest for 1 year (n5 = 65= 1 year) 6^{th} installment will have no interest (n6 = 66= 0 years)
Total Amount = 6 Installments + Interest on those 6 Installments
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


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

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

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

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%

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

