$1-$ An athlete needs to go on a diet during preparation for a competition. The dietitian advises various foods $($VF$)$ that

the athlete can select from, please see table below. However, athlete does not have much money due to his fund not

being approved. Thus, the athlete does a bit of research and creates the table below, in which P$,$ F$,$ C$,$ CPU, MR means

proteins, fats, carbohydrates, cost per unit in dollars, minimum requirement, respectively. Please formulate a linear

programming model solving to indicate which can help the athlete to find out how much of each food he should take

to minimize his costs while meeting the minimum requirements $($you do not need to solve the model$).$