Rs. 2100 is lent at compound interest of 5% per annum for 2 years. Find the amount after two years.
A. Rs. 2300
B. Rs. 2315.25
C. Rs. 2310
D. Rs. 2320
E. None of these
Answer: Option B
Solution (By Examveda Team)
$$\eqalign{ & {\text{We}}\,{\text{can}}\,{\text{use}}\,{\text{formula}}\,{\text{of}}\,{\text{compound}}\,{\text{interest}} \cr & A = P \times {\left[ {1 + \left( {\frac{r}{{100}}} \right)} \right]^n} \cr & A = 2100 \times {\left[ {1 + \left( {\frac{5}{{100}}} \right)} \right]^2} \cr & A = 2100 \times {\left[ {\frac{{105}}{{100}}} \right]^2} \cr & A = \frac{{ {2100 \times 11025} }}{{10000}} \cr & {\text{Hence,}}\,{\text{Amount}}\,A = Rs.\,2315.25 \cr} $$This Question Belongs to Arithmetic Ability >> Interest
How do you have 105
isn't there more short cut method ?
How it's 105
We can use formula of compound interest;
A = P*[1+ (r/100)]n
A = 2100*[1+(5/100)]2
A = 2100*[105/100]2
A = (2100*11025)/10000
Hence, Amount, A = Rs. 2315.25.