On a chicken farm, the poultry is given a healthy diet to gain weight. The chickens must consume a minimum of 25 units of Substance A and another 35 units of Substance B. In the market, there are only two classes of compounds: Type X, with a composition of one unit of A to five units of B, and another type, Y, with a composition of five units of A to one of B. The price of Type X is $10 and Type Y, $30. What are the quantities of each type of compound that must be purchased to cover the needs of the diet with a minimal cost?