Find $\displaystyle {A}$, in lowest terms, if the graphs of the equations $\displaystyle {A}{x}-{5}{y}=-{10}$ and $\displaystyle -{15}{x}+{12}{y}={13}$ are:

(i)   parallel:  $\displaystyle {A}=$ 

(ii)  perpendicular:  $\displaystyle {A}=$