Aptitude - Compound Interest - Discussion
Discussion Forum : Compound Interest - General Questions (Q.No. 8)
8.
The least number of complete years in which a sum of money put out at 20% compound interest will be more than doubled is:
Answer: Option
Explanation:
| P |  |
1 + | 20 |  |
n | > 2P |  |
|
6 | |
n | > 2. |
| 100 | 5 |
| Now, | |
6 | x | 6 | x | 6 | x | 6 | |
> 2. |
| 5 | 5 | 5 | 5 |
So, n = 4 years.
Discussion:
26 comments Page 2 of 3.
Shubham said:
9 years ago
What is the least number of complete years in which sum will become more than double itself at 12% per annum?
Given me the answer with clear explanation.
Given me the answer with clear explanation.
(1)
Ashok said:
9 years ago
@Kalyani.
In question, they asked how much of year will give the principal amount doubled so the only 2p is used.
In question, they asked how much of year will give the principal amount doubled so the only 2p is used.
Lokesh said:
8 years ago
Easy method.
How Will know n=72/r?
How Will know n=72/r?
Dilip said:
9 years ago
@Kalyani
Suppose double principle then 2p.
Triple principle then 3p.
I hope you can understand.
Suppose double principle then 2p.
Triple principle then 3p.
I hope you can understand.
Dhairya adhikari said:
9 years ago
Easy method:
n = 72/r,
n = 72/20 = 3.6 years,
n = 4 years approximately.
n = 72/r,
n = 72/20 = 3.6 years,
n = 4 years approximately.
Abinash said:
2 decades ago
Dear friends, Can anybody tell me in brief how it is done please?
Kalyani said:
9 years ago
Why are we using 2p?
Ritesh said:
10 years ago
Hello @Anjali,
First take Amount = Rs. 5000 and Rate = 2%, Years = 1.
Then calculate SI, SI = PNR/100.
So, SI = 5000*1*2/100 = RS. 100.
[Here you are getting only interest].
Now calculate CI, CI = P(1+r)^n.
So, CI = 5000*(1+2/100)^1 = RS. 5100.
[Here we are getting Interest+Principal amount].
First take Amount = Rs. 5000 and Rate = 2%, Years = 1.
Then calculate SI, SI = PNR/100.
So, SI = 5000*1*2/100 = RS. 100.
[Here you are getting only interest].
Now calculate CI, CI = P(1+r)^n.
So, CI = 5000*(1+2/100)^1 = RS. 5100.
[Here we are getting Interest+Principal amount].
Anjali said:
10 years ago
I am unable to understand why are taking amount formula in place of CI. Please explain it.
Swathi said:
1 decade ago
Hi,
We are using > 2. Can you explain it?
We are using > 2. Can you explain it?
Post your comments here:
Quick links
Quantitative Aptitude
Verbal (English)
Reasoning
Programming
Interview
Placement Papers