29. You're on your way to a friend's house for dinner, and it's up to you to design the dessert. You know a wonderful recipe for chocolate cake. For 6 people, the ingredients are: 250 g butter, 200 g sugar, 300 g chocolate, 6 eggs and 3 spoonfuls of flour. But your friend is only entertaining 4 people. In this case, what are the required quantities for each ingredient in the recipe?