Aptitude - Compound Interest - Discussion
Discussion Forum : Compound Interest - General Questions (Q.No. 2)
2.
The difference between simple and compound interests compounded annually on a certain sum of money for 2 years at 4% per annum is Re. 1. The sum (in Rs.) is:
Answer: Option
Explanation:
Let the sum be Rs. x. Then,
| C.I. = |  |
x |  |
1 + | 4 |  |
2 | - x |  |
= | |
676 | x | - x | |
= | 51 | x. |
| 100 | 625 | 625 |
| S.I. = | |
x x 4 x 2 | |
= | 2x | . |
| 100 | 25 |
 |
51x | - | 2x | = 1 |
| 625 | 25 |
x = 625.
Discussion:
149 comments Page 5 of 15.
Monalisa said:
1 decade ago
Hey guys, I have a shortcut formula for such problem:
p = d*100^2/r^2 (only for 2 yrs).
Where p = principle.
d = difference.
r = rate.
p = d*100^2/r^2 (only for 2 yrs).
Where p = principle.
d = difference.
r = rate.
Krunal bhut said:
9 years ago
Interest of interest of amount is difference between SI and CI at rate given,
4% of x = 0.04x,
4% of 0.04x = (0.04x)4/100 = 1,
x = 625.
4% of x = 0.04x,
4% of 0.04x = (0.04x)4/100 = 1,
x = 625.
Arun raj said:
9 years ago
CI - SI = P(r/100)square
P = principal,
R = rate = 4.
CI - SI = 1.
=>. 1 = p(4/100)square.
1= p(1/25)square,
1= p(1/625),
P = 625.
P = principal,
R = rate = 4.
CI - SI = 1.
=>. 1 = p(4/100)square.
1= p(1/25)square,
1= p(1/625),
P = 625.
MANAS BISWAL said:
1 decade ago
(C.I)2 - (S.I)2 = 1.
SUCCESSIVE DISCOUNT(C.I) = 4+4(4*4/100) = 8.16.
(S.I) 4+4 = 8.
8.16-8 = 0.16 .
0.16/1*100 = 625.
SUCCESSIVE DISCOUNT(C.I) = 4+4(4*4/100) = 8.16.
(S.I) 4+4 = 8.
8.16-8 = 0.16 .
0.16/1*100 = 625.
Prasanna Karthik said:
9 years ago
We can use the direct formula for this one.
The difference after 2 years = PR^2/100^2.
Here, P - Principal, R - Interest of Rate.
The difference after 2 years = PR^2/100^2.
Here, P - Principal, R - Interest of Rate.
Praveen said:
1 year ago
we have difference formula for this question and that is;
CI - SI = P(R/100)^2,
1 = P(4/100)^2,
1 = P(1/25)^2,
1 = P /625.
625 = P.
CI - SI = P(R/100)^2,
1 = P(4/100)^2,
1 = P(1/25)^2,
1 = P /625.
625 = P.
(20)
Viji said:
1 decade ago
shotcut method:
If you give the difference between si and ci for 2 years means,
4*4/100
=.16
1/.16*100
100/16*100
100/4*25
625
If you give the difference between si and ci for 2 years means,
4*4/100
=.16
1/.16*100
100/16*100
100/4*25
625
Manu said:
1 decade ago
The question is to find the sum of CI & SI. The answer we got is the principle, not the sum. Please correct if I am Wrong.
Goutham said:
2 decades ago
Hai I am Goutham.
Can anyone help me out , why are we using -x in the step one..
Please help me out
Thanks in advance...
Can anyone help me out , why are we using -x in the step one..
Please help me out
Thanks in advance...
(1)
Bhavani said:
6 years ago
Principal = X say.
C.I = Amount-Principal.
= {X[1+4/100]^2-X}.
S.I = [ X(4)(2)/100].
C.I = Amount-Principal.
= {X[1+4/100]^2-X}.
S.I = [ X(4)(2)/100].
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