Aptitude - Compound Interest - Discussion
Discussion Forum : Compound Interest - General Questions (Q.No. 3)
3.
There is 60% increase in an amount in 6 years at simple interest. What will be the compound interest of Rs. 12,000 after 3 years at the same rate?
Answer: Option
Explanation:
Let P = Rs. 100. Then, S.I. Rs. 60 and T = 6 years.
 R = |
 |
100 x 60 |  |
= 10% p.a. |
| 100 x 6 |
Now, P = Rs. 12000. T = 3 years and R = 10% p.a.
| C.I. |
|
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|
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| = 3972. |
Discussion:
94 comments Page 5 of 10.
Aashi said:
7 years ago
Please tell me how 331 is coming? Please explain me.
MONI SHANKAR said:
8 years ago
1200*(11/10)*(11/10)*(11/10)=15972.
CI=15972-12000=3972,
P.S : (HERE 11/10=110/100 WHICH MEANS 10% RATE AND CAME FROM STATEMENT 60% INCREMENT IN 6 YEARS.)
CI=15972-12000=3972,
P.S : (HERE 11/10=110/100 WHICH MEANS 10% RATE AND CAME FROM STATEMENT 60% INCREMENT IN 6 YEARS.)
Sarojkumarnaik786@gmail.com said:
1 decade ago
Generally we know the formula of amount not C.I.
Amount = P(1+ R\100)^t.
If we find C.I then we should subtract the principal, then the formula changes to C.I = P((1 + R/100)^t -- 1).
Amount = P(1+ R\100)^t.
If we find C.I then we should subtract the principal, then the formula changes to C.I = P((1 + R/100)^t -- 1).
Anmol said:
1 decade ago
@Karthi & Vasanth: you can take any value of P instead of 100.
100 is taken just for simplicity of calculation.
Now, as there is 60% rise in principal in 6 years
therefore, Net amount after 6 years, A= P+ 60% of P =1.6P
therefore interest,I= 1.6P-P= .6P
using SI formula, I= PTR/100
so, 0.6P= P*6*R/100
-> 60=6R
-> R=10%
100 is taken just for simplicity of calculation.
Now, as there is 60% rise in principal in 6 years
therefore, Net amount after 6 years, A= P+ 60% of P =1.6P
therefore interest,I= 1.6P-P= .6P
using SI formula, I= PTR/100
so, 0.6P= P*6*R/100
-> 60=6R
-> R=10%
Javeed said:
2 decades ago
Dude here principle is Rs. 12000, so amount = P(1+r/100)^t
C.I = amount - principle i.e., p((1+r/100)^t )-p
Removing 'p' common factor we get:
p((1+(R/100)^T)-1)
HERE 1200 IS REMOVED AS COMMON FACTOR SINCE IT IS THE VALUE OF P.
C.I = amount - principle i.e., p((1+r/100)^t )-p
Removing 'p' common factor we get:
p((1+(R/100)^T)-1)
HERE 1200 IS REMOVED AS COMMON FACTOR SINCE IT IS THE VALUE OF P.
Priya said:
2 decades ago
Thanks Jeeva. Now I also clear abut this problem.
Anurag said:
2 decades ago
Thanks a lot. Now it became very easy.
Kusum said:
1 decade ago
Any one tel me how we got R value as 10?
Amit said:
1 decade ago
@Kusum
Simple interest formula
SI = PRN / 100
So, SI * 100 = PRN which derives new formula for R as
R = (SI * 100) / PN
Let P = Rs. 100. Then, S.I. Rs. 60 and T = 6 years.
Put all this into simple interest formula
R = (100 x 60 ) / 100 x 6 = 10% p.a.
Hope you will get it :)
Simple interest formula
SI = PRN / 100
So, SI * 100 = PRN which derives new formula for R as
R = (SI * 100) / PN
Let P = Rs. 100. Then, S.I. Rs. 60 and T = 6 years.
Put all this into simple interest formula
R = (100 x 60 ) / 100 x 6 = 10% p.a.
Hope you will get it :)
Karthi said:
1 decade ago
How we get P = Rs.100 and S.I = Rs. 60 ?
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