Aptitude - Compound Interest - Discussion
Discussion Forum : Compound Interest - General Questions (Q.No. 15)
15.
The compound interest on a certain sum for 2 years at 10% per annum is Rs. 525. The simple interest on the same sum for double the time at half the rate percent per annum is:
Answer: Option
Explanation:
Let the sum be Rs. P.
| Then, |  |
P |  |
1 + | 10 |  |
2 | - P |  |
= 525 |
| 100 |
 |
P | |
|
11 | |
2 | - 1 | |
= 525 |
| 10 |
| P = |
|
525 x 100 | |
= 2500. |
| 21 |
Sum = Rs . 2500.
| So, S.I. = Rs. | |
2500 x 5 x 4 | |
= Rs. 500 |
| 100 |
Discussion:
37 comments Page 2 of 4.
Varalaksmi said:
1 decade ago
Hai I think this way may be correct for finding the value of p.
p = (121/100-1).
p = (121-100/100).
p = (21/100).
p = (21/100) = Rs.525.
So, p = (525*100)/21.
p = Rs.2500.
p = (121/100-1).
p = (121-100/100).
p = (21/100).
p = (21/100) = Rs.525.
So, p = (525*100)/21.
p = Rs.2500.
Mujahid Aziz said:
7 years ago
Given that ;
p*21/100=525,
so P= 525*100/21,
p=2500.
Now S.I= PTR/100.
where time is doubled So T=4 and Rate is halved So R=5.
Now S.I= 2500*4*5/100.
S.I =500.
p*21/100=525,
so P= 525*100/21,
p=2500.
Now S.I= PTR/100.
where time is doubled So T=4 and Rate is halved So R=5.
Now S.I= 2500*4*5/100.
S.I =500.
(1)
Sanjeev Sharma said:
9 years ago
We can always take base as 100.
On 100 CI for 2 yrs @10% = 21,
Now since CI is 525, therefore, P = 100 ÷ 21 * 525 = 2500,
Now SI = 2500 * 10 * 2 ÷ 100 = 500.
On 100 CI for 2 yrs @10% = 21,
Now since CI is 525, therefore, P = 100 ÷ 21 * 525 = 2500,
Now SI = 2500 * 10 * 2 ÷ 100 = 500.
Tanisha said:
5 years ago
@Babai.
When you divide 10/100 it will give you 1/10 then when you will add it with one it will give you 11/10. Actually it comes in the mixed fraction.
When you divide 10/100 it will give you 1/10 then when you will add it with one it will give you 11/10. Actually it comes in the mixed fraction.
Lokesh said:
1 year ago
Hello guys.
The simplest way is;
Here the sum will be the same.
C. I for 2yrs@10%p.a is;
21% = 525.
For S.I 4yrs @5 % p.a is;
20% = 500.
The simplest way is;
Here the sum will be the same.
C. I for 2yrs@10%p.a is;
21% = 525.
For S.I 4yrs @5 % p.a is;
20% = 500.
(2)
Pratiksha said:
8 years ago
Can anybody tell me when to use this formula?
P*(1+R/100)^-P.
and when to use,
P*(1+R/100)^.
Please, explain it.
P*(1+R/100)^-P.
and when to use,
P*(1+R/100)^.
Please, explain it.
Sikun said:
1 decade ago
CI=Amount-Principle.
And we know the CI, but don't know Principle. So to find P we are subtracting P.
And we know the CI, but don't know Principle. So to find P we are subtracting P.
Tanisha said:
5 years ago
@Nisha.
Actually they take the common factor so when we take p common there it is replaced by 1.
Actually they take the common factor so when we take p common there it is replaced by 1.
(2)
Tony said:
7 years ago
It should be 121 instead of 21 cuz 11^2=121,
525=p(1+10/100)^2,
525=p(110/100)^2.
525=p(1+10/100)^2,
525=p(110/100)^2.
Mounika said:
9 years ago
Is there any shortcut way to solve this problem? If yes means please share.
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