1. The ratio of ingredients is 3 (potatoes) : 3 (beef) : 8 (vegetables). 2. The amount of beef is 720 g, which corresponds to 3 parts of the ratio. Therefore, 1 part = 720 g / 3 = 240 g. 3. The total mass of potatoes and vegetables is (3 + 8) parts = 11 parts. 4. The total mass of potatoes and vegetables = 11 parts * 240 g/part = 2640 g.