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 11 of 15.
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.
Prasanna Kumar said:
9 years ago
SI for 2 yrs = 4% +4%.
i.e * 8%.
And CI for 2 yrs = 4+4+(4*4/100) i.e 8.16% .
Then take the options,
Given difference is ci - si = 1.
8.16% (625) - 8% (625).
ie, 51- 50 = 1.
i.e * 8%.
And CI for 2 yrs = 4+4+(4*4/100) i.e 8.16% .
Then take the options,
Given difference is ci - si = 1.
8.16% (625) - 8% (625).
ie, 51- 50 = 1.
Mahan Singh said:
9 years ago
Its very simple we put -x because the question is asking the difference between Interest but in compound interest formula we also put the principal value together to subtract that we will - x because x is principal value. We don't need principal value only we need interest difference.
MALINIMADHAVAN said:
9 years ago
S.I = PNR/100.
=(PX2X4)/100,
=(PX2X1)/25.
THEREFORE S.I = PX2/25 = 0.008P,
C.I = P(1+R/100)^N -P,
= P(1+4/100)^2 -P,
=P(1+1/25)^2 - P,
= P(25+1/25)^2 -P,
= P(26/25)^2-P,
= P(1.04)^2-P,
= P(1.0816)-P,
=1.0816P-P.
C.I =.0816P.
DIFFERENCE:
CI-SI = 1
0.0816P - 0.08P =1,
0.0016P = 1,
P = 1/0.0016 = 625.
THEREFORE, SUM IN RUPEES IS 625Rs.
=(PX2X4)/100,
=(PX2X1)/25.
THEREFORE S.I = PX2/25 = 0.008P,
C.I = P(1+R/100)^N -P,
= P(1+4/100)^2 -P,
=P(1+1/25)^2 - P,
= P(25+1/25)^2 -P,
= P(26/25)^2-P,
= P(1.04)^2-P,
= P(1.0816)-P,
=1.0816P-P.
C.I =.0816P.
DIFFERENCE:
CI-SI = 1
0.0816P - 0.08P =1,
0.0016P = 1,
P = 1/0.0016 = 625.
THEREFORE, SUM IN RUPEES IS 625Rs.
KarthicK said:
9 years ago
@Sudharsan.
Clear explanation Thanks.
Clear explanation Thanks.
Shivesh said:
9 years ago
Derivation of this formula.
Principal x (r%/100)^2 = Difference between interests.
Principal x (r%/100)^2 = Difference between interests.
Prasad Mandati said:
8 years ago
Note:
If,
P= Principal sum x= R/100.
Now,
The difference between Compound and simple interests when compounded annually for two years is Px^2.
Similarly if the same is done for 3 years the difference would be P(x^3 + 3x^2).
Hope it helps you!
If,
P= Principal sum x= R/100.
Now,
The difference between Compound and simple interests when compounded annually for two years is Px^2.
Similarly if the same is done for 3 years the difference would be P(x^3 + 3x^2).
Hope it helps you!
Nilesh said:
9 years ago
How 51/625 comes? Please explain that.
Yashika said:
8 years ago
The SI = CI when the principal and rate are the same and time is ________.
Please give me the answer.
Please give me the answer.
Remya said:
8 years ago
Anu deposit some money in a bank. After 6 years he got 6500rs, then after 2 years, she got 7800 rs. The how much amount will she get after 10 years?
Can anyone solve this?
Can anyone solve this?
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