Aptitude Simple And Compound InterestPage 2
9. | | A sum of ₹12500 amounts to ₹15500 in 4 years at the rate of simple interest. What is the rate of interest? | | (a)3% | | (b)4% | | (c)5% | | (d)6% |
|
Answer is: DS.I. = Rs (15500 - 12500) = Rs. 3000
Rate = (100 x 3000)/(12500 x 4) = 6%
10. | | Rs. 800 becomes Rs. 956 in 3 years at a certain rate of simple interest. If the rate of interest is increased by 4%, what amount will Rs. 800 become in 3 years? | | (a)Rs. 1020.80 | | (b)Rs. 1025 | | (c)Rs. 1052 | | (d)Data inadequate |
|
Answer is: CS.I. = (956 - 800) = 156.
R = (100 x 156)/(800 x 3) = 13/2%
New rate = [(13/2) + 4] = 21/2%
New S.I. = (800 x 21/2 x 3/100) = Rs. 252
New amount = Rs. (800 + 252) = Rs. 1052.
11. | | A certain amount earns simple interest of Rs. 1750 after 7 years. Had the interest been 2% more, how much more interest would it have earned? | | (a)Rs.35 | | (b)Rs. 245 | | (c)Rs. 350 | | (d)cannot be determined |
|
Answer is: DWe need to know the S.I., principal and time to find the rate. Since the principal is not given , so data is inadequate.
12. | | In how many years, Rs. 150 will produce the same interest at the rate 8% as Rs. 800 produce in 3 years at the rate 9/2%? | | (a)6 | | (b)8 | | (c)9 | | (d)12 |
|
Answer is: CGiven , P = 800
R = 9/2 = 9/2%
T = 3
Then, S.I. = (800 x 9/2 x 3/100) = 108.
Now, P = 150
S.I. = 108
R = 8%
T = (100 x 108)/(150 x 8) = 9 years.
13. | | What will be the ratio of simple interest earned by certain amount at the same rate of interest for 4 years and that for 12 years ? | | (a)1:3 | | (b)1:4 | | (c)2:3 | | (d)Data inadequate |
|
Answer is: ALet the principal be P and rate of interest be R%.
So, Required ratio = [(PR × 4)/100]/[PR × 12]/100
= 4PR/12PR
= 4/12
= 1:3.
14. | | A sum of money at simple interest amounts to ₨ 817 in 3 years and to ₨ 852 in 4 years. The sum is: | | (a): 650 | | (b): 712 | | (c): 798 | | (d): 700 |
|
Answer is: BS.I. for 1 year = (852 - 817) = 35
S.I. for 3 years = 35 × 3 = 105.
∴   Principal = ₨ (817-105) = 712.
15. | | Rahul invested an amount of ₨ 14000 at the rate of 8% per annum simple interest and another amount at the rate of 20% per annum simple interest. The total interest earned at the end of one year on the total amount invested became 14% par annum. Find the total amount invested? | | (a)28000 | | (b)26000 | | (c)24000 | | (d)25000 |
|
Answer is: ALet the second amount be ₨ X. Then,
(14000 × 8 × 1)/100 + (X × 20 × 1)/100 = [(14000 + X) × 14 × 1]/100
∴   112000 + 20X = 196000 + 14X
X = 14000
Hence, the total investment   14000 + 14000 = 28000.
16. | | Mr. William invested an amount of ₨ 13000 divided in two different schemes A and B at the simple interest rate of 15% par annum and 10% par annum respectively. If the total amount of simple interest earned in 2 years be ₨ 3510, What was the amount invested in scheme B ? | | (a)4000 | | (b)4500 | | (c)3900 | | (d)3950 |
|
Answer is: CLet the sum invested in scheme A be Rs. X and that in scheme B be ₨ (13000 - X).
Then,   (X × 15 × 2)/100 + [(13000 - X) × 10 × 2]/100 = 3510
30X - 20X = 351000 - (13000 × 20)
    10X = 91000
    X = 9100.
So, sum invested in Scheme B = ₨ (13000 - 9100) = 3900
Comments