In a chicken farm a diet is given, to gain weight, with a minimum composition of 15 units of a substance A and another 15 of a substance B.
There are only two classes of compounds on the market: type X with a composition of one
unit of A and 5 of B, and the other type, Y, with a composition of five units of A and one of B. The
price of type X is $ 10 and type Y is $ 30.
What quantities of each type must be purchased to cover the needs at a cost
minimum?