Quantitative Aptitude Ques 377
Question: The compound interest on Rs. 30000 at 7% per annum for a certain time a Rs. 4347. The time is
[IBPS (Office Assistant) 2015]
Options:
A) 2 yr
B) 2.5 yr
C) 3 yr
D) 4 yr
E) None of these
Show Answer
Answer:
Correct Answer: A
Solution:
- $ CI=P{{( 1+\frac{r}{100} )}^{n}}-P $
$ \Rightarrow $ $ 4347=30000{{( 1+\frac{7}{100} )}^{n}}-30000 $
$ \Rightarrow $ $ 4347=30000[ {{( 1+\frac{7}{100} )}^{n}}-1 ] $
$ \Rightarrow $ $ 4347=30000[ {{( \frac{107}{100} )}^{n}}-1 ] $
$ \Rightarrow $ $ \frac{4347}{30000}=[ {{( \frac{107}{100} )}^{n}}-1 ] $
$ \Rightarrow $ $ \frac{4347}{30000}+1={{( \frac{107}{100} )}^{n}} $
$ \Rightarrow $ $ \frac{34347}{30000}={{( \frac{107}{100} )}^{n}} $
$ \Rightarrow $ $ \frac{11449}{10000}={{( \frac{107}{100} )}^{n}} $
$ \Rightarrow $ $ {{( \frac{107}{100} )}^{n}}={{( \frac{107}{100} )}^{n}} $
$ \therefore $ $ n=2,yr $
BETA
