| The compound interest on Rs. 30000 at 7% per annum for a certain time a Rs. 4347. The time is |
| [IBPS (Office Assistant) 2015] |
A) 2 yr
B) 2.5 yr
C) 3 yr
D) 4 yr
E) None of these
Correct Answer: A
Solution :
| \[CI=P{{\left( 1+\frac{r}{100} \right)}^{n}}-P\] |
| \[\Rightarrow \] \[4347=30000{{\left( 1+\frac{7}{100} \right)}^{n}}-30000\] |
| \[\Rightarrow \] \[4347=30000\left[ {{\left( 1+\frac{7}{100} \right)}^{n}}-1 \right]\] |
| \[\Rightarrow \] \[4347=30000\left[ {{\left( \frac{107}{100} \right)}^{n}}-1 \right]\] |
| \[\Rightarrow \] \[\frac{4347}{30000}=\left[ {{\left( \frac{107}{100} \right)}^{n}}-1 \right]\] |
| \[\Rightarrow \]\[\frac{4347}{30000}+1={{\left( \frac{107}{100} \right)}^{n}}\]\[\Rightarrow \]\[\frac{34347}{30000}={{\left( \frac{107}{100} \right)}^{n}}\] |
| \[\Rightarrow \]\[\frac{11449}{10000}={{\left( \frac{107}{100} \right)}^{n}}\]\[\Rightarrow \]\[{{\left( \frac{107}{100} \right)}^{n}}={{\left( \frac{107}{100} \right)}^{n}}\] |
| \[\therefore \] \[n=2\,yr\] |
You need to login to perform this action.
You will be redirected in
3 sec
