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. |
|
|||||||||||||
|
||||||||||||||
| = 3972. |
Discussion:
94 comments Page 5 of 10.
Vani said:
10 years ago
Suppose principle is 100.
Then simple interest becomes 60.
Then rate will become 10% by using the formula,
(ptr)/100 = simple interest.
Now the compound interest in 3 years with the rate 10% is,
10+10+1(interest on interest)+11+1.1 = 33.1.
12000 --- 100
?----------- 33.1
The answer is 3972.
Then simple interest becomes 60.
Then rate will become 10% by using the formula,
(ptr)/100 = simple interest.
Now the compound interest in 3 years with the rate 10% is,
10+10+1(interest on interest)+11+1.1 = 33.1.
12000 --- 100
?----------- 33.1
The answer is 3972.
Durga said:
9 years ago
@ All, Guys your discussions are very useful. Thank you all.
Thejus said:
9 years ago
@Josephlecocq.
What is -1 as p?
What is -1 as p?
Vikash said:
9 years ago
After taking common factor p from bracket then automatically -1 come i.e. -1 * p = -p.
If you are confused about -1 then don't take common answer come same but it becomes some complicated.
If you are confused about -1 then don't take common answer come same but it becomes some complicated.
Prabhakaran said:
9 years ago
Hi, can anyone explain to me why CI = Amount - P if its P we can substitute the actual principal.
Malleswar said:
9 years ago
Beautifully explained. Thanks to all.
Arvindsamy said:
9 years ago
Guys your discussions and solutions are very useful. Thank you all guys.
BLESSING said:
9 years ago
The formula for compound interest:.
A = P (1 + r) ^n.
Now, P = 12000.
A = ?
N = 3.
From the first statement, there was 60% increase in an amount for 6 years simple interest.
Let the amount (P) be 100 then SI=60, SI = PIN.
60 = 100 * I * 6,
60 = 600 I,
I = 0.1.
Since we have 0.1 x 100 = 10%.
Now A = 12000 (1 + 1/10)^3
= 12000 (11/10)^3,
= 12000 (11/10 x 11/10 x 11/10),
= 12000 (1331/1000) = 15,972.
So, A = 15972, P = 12000 then,
CI = 15972 - 12000 = 3972.
A = P (1 + r) ^n.
Now, P = 12000.
A = ?
N = 3.
From the first statement, there was 60% increase in an amount for 6 years simple interest.
Let the amount (P) be 100 then SI=60, SI = PIN.
60 = 100 * I * 6,
60 = 600 I,
I = 0.1.
Since we have 0.1 x 100 = 10%.
Now A = 12000 (1 + 1/10)^3
= 12000 (11/10)^3,
= 12000 (11/10 x 11/10 x 11/10),
= 12000 (1331/1000) = 15,972.
So, A = 15972, P = 12000 then,
CI = 15972 - 12000 = 3972.
(1)
Renu said:
9 years ago
10% successive of 3 years is 33.1%
33.1% of 12000.
= 3972.
33.1% of 12000.
= 3972.
Angad said:
9 years ago
How to find the rate of interest if compound interest and principle and time is already given but the rate is missing? I need the solution.
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