Compound Interest - Aptitude MCQ Questions and Solutions with Explanations

Answer: Option A

Interest for 2 years at the rate of 15%
$$\eqalign{ & {\text{ = 15 + 15 + }}\frac{{15 \times 15}}{{100}} \cr & = 32.25\% \cr & {\text{According to question,}} \cr & {\text{32}}{\text{.25}}\% {\text{ = 3225}} \cr & {\text{100}}\% {\text{ = }}\frac{{3225}}{{32.25}} \times 100 \cr & = 100 \times 100 = 10000 \cr} $$

Answer: Option A

$$\eqalign{ & {\text{10}}\% {\text{ = }}\frac{1}{{10}} \cr & {\text{Principal}}\,\,\,\,\,\,\,{\text{Amount}} \cr & \,\,\,\,\,\,\,{\text{10}}\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,11 \cr & \,\,\,\,\,\,\,{\text{10}}\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,11 \cr & \,\,\,\,\,\,\,{\text{10}}\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,11 \cr & \,\,\,\,\,\,\,{\text{10}}\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,11 \cr & \underbrace {\overline {\,\,\,10000\,\,\,\,\,\,{\text{:}}\,\,\,\,\,{\text{14641}}\,\,\,} }_{{\text{CI = 4641}}} \cr & \because {\text{Principal = 10000 units}} \cr & {\text{ = Rs}}{\text{. 4000 (given)}} \cr & {\text{1 unit = }}\frac{2}{5} \cr & {\text{CI = 4641 unit}} \cr & {\text{ = Rs}}{\text{. }}\left( {\frac{2}{5} \times 4641} \right) \cr & = {\text{Rs}}{\text{. }}1856.40 \cr} $$