Diverse Footware Sdn. Bhd. uses leather and synthetic to produce two types of casual shoes, WeStar X and MeStar Y. A WeStar X shoe requires 20 cm of leather, 30 cm of synthetic and 1 hour of labor. A MeStar Y shoe requires 30 cm of leather, 20 cm of synthetic and 2 hours of labor. Each WeStar X shoe sells for RM75, and each MeStar Y shoe sells for RM90. All shoes produced by Diverse Footware can be sold. At present, Diverse Footware has 10 meters of leather, 12 meters of synthetic and 70 hours of labor. Extra leather can be purchased at a cost of RM4.50 per centimeter. Market demand requires that the company produce at least 20 WeStar X shoes but demand for MeStar Y shoes is unlimited. (a) Formulate a mathematical model to maximize Diverse Footware profit. (b) Solve the mathematical model by using the Big M Method