The monthly incomes of A and B are in ratio 3 : 5 and the ratio of their saving is 2 : 3. If the income of B is equal to three times the saving of A, then what is the ratio of the expenditures of A and B?

\[\begin{array}{*{20}{c}} {}&{\text{A}}&{}&{\text{B}} \\ {{\text{Income}} \to }&{3x}&:&{5x} \\ {{\text{Saving}} \to }&{2y}&:&{3y} \end{array}\]
$$\eqalign{ & 5x = 3 \times 2y \cr & \frac{x}{y} = \frac{6}{5} \cr} $$
\[\begin{array}{*{20}{c}} {}&{\,{\text{A}}\,\,\,\,\,{\text{B}}\,} \\ {{\text{Income}} \to }&{18\,\,\,\,30} \\ {{\text{Saving}} \to }&{10\,\,\,\,15} \\ {{\text{Expenditure}} \to }&{\overline {\,\,\,8\,:\,15\,\,} } \end{array}\]