Aptitude - Compound Interest - Discussion
Discussion Forum : Compound Interest - General Questions (Q.No. 5)
5.
The compound interest on Rs. 30,000 at 7% per annum is Rs. 4347. The period (in years) is:
Answer: Option
Explanation:
Amount = Rs. (30000 + 4347) = Rs. 34347.
Let the time be n years.
| Then, 30000 |  |
1 + | 7 |  |
n | = 34347 |
| 100 |
 |
|
107 | |
n | = | 34347 | = | 11449 | = | |
107 | |
2 |
| 100 | 30000 | 10000 | 100 |
n = 2 years.
Discussion:
46 comments Page 1 of 5.
Soniya said:
2 years ago
Simple method :
Amount of Rs.30000 x 7/100 = 2100 first year
Next year we calculate compound interest so RS. 30000+2100 add the previous year's interest.
Rs.32100 x 7/100 = 2247 => second year interest.
First-year interest : Rs.2100
Second-year interest : Rs.2247
Total Rs.4347
So, the answer is 2 years.
Amount of Rs.30000 x 7/100 = 2100 first year
Next year we calculate compound interest so RS. 30000+2100 add the previous year's interest.
Rs.32100 x 7/100 = 2247 => second year interest.
First-year interest : Rs.2100
Second-year interest : Rs.2247
Total Rs.4347
So, the answer is 2 years.
(61)
Migma Tshering Tamang said:
5 years ago
34347=30000(1+0.07)^n.
1.1449=(1.07)^n.
Using log in both the side.
log1.1449=n * log1.07.
n=log1.1449/log1.07.
n=2 years.
1.1449=(1.07)^n.
Using log in both the side.
log1.1449=n * log1.07.
n=log1.1449/log1.07.
n=2 years.
(8)
Narsim Bari said:
7 years ago
30000*7/100 = 2100 for 1rst year.
For 2nd year : 30000+2100*7/100 = 2247.
Now, cross-check the given calculated amount given in the question itself i.e 4347 rupees by adding 2 years amount (2100+2247)=4347.
Believe this is the fastest and tricky method of our natural mind.
For 2nd year : 30000+2100*7/100 = 2247.
Now, cross-check the given calculated amount given in the question itself i.e 4347 rupees by adding 2 years amount (2100+2247)=4347.
Believe this is the fastest and tricky method of our natural mind.
(7)
Garima said:
4 years ago
Can anyone please tell me how (1+7/100) become (107+100)?
(5)
Akash Kumar Sinha said:
8 years ago
1st year CI= 7% OF 30000 ie 2100.
2nd year CI=2100+ 7% of 2100 ie 147.
2100+2100+147=4347.
Hence, 2 years.
2nd year CI=2100+ 7% of 2100 ie 147.
2100+2100+147=4347.
Hence, 2 years.
(4)
Nitish said:
3 years ago
No @Garima.
You should write it as 107/100 which came by the basic addition method.
You should write it as 107/100 which came by the basic addition method.
(3)
Saron said:
4 years ago
Very good, Thanks everyone for explaining.
(2)
Lokesh said:
6 years ago
Verify with given option.
CI =7 %
1ST YEAR 7%.
For 2nd year, it becomes 7.49
Total 14.49
If 100% = 30K.
Then 114.49 = ?
(114.49 * 30K)÷100.
And you will get 4347.
CI =7 %
1ST YEAR 7%.
For 2nd year, it becomes 7.49
Total 14.49
If 100% = 30K.
Then 114.49 = ?
(114.49 * 30K)÷100.
And you will get 4347.
(1)
Priya said:
8 years ago
What is 107/100? I can't understand, please explain.
(1)
Prasad said:
7 years ago
Why we square that 107/100 n=2? why? please.
(1)
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