If a = b × $$\frac{{d}}{{c}}$$; b, c and d are increased by 10%, then by how much does a increase ?

$$\eqalign{ & {\text{Let,}} \cr & B = 110\% {\text{ of }}b = \frac{{11b}}{{10}}{\text{ }} \cr & C = 110\% {\text{ of }}c = \frac{{11c}}{{10}} \cr & D = 110\% {\text{ of }}d = \frac{{11d}}{{10}} \cr & {\text{Then,}} \cr & A = B \times \frac{D}{C} \cr & A = \frac{{11b}}{{10}} \times \frac{{11d}}{{10}} \times \frac{{10}}{{11c}} \cr & A = \frac{{11bd}}{{10c}} \cr & A = \frac{{11}}{{10}}a \cr & A = \frac{{110}}{{100}}a \cr & A = 110\% {\text{ of }}a \cr & \therefore {\text{ Increase }}\% = 10\% \cr} $$