Another application of multisets is in tracking resources. Suppose that baking bread requires three units of flour, one unit of yeast, and one unit of salt:

B = {3 ·Flour,1 ·Yeast,1 ·Salt}.

Baking a cake requires one unit of flour, two units of sugar, one unit of butter, and one unit of eggs:

C = {1 ·Flour,2 ·Sugar,1 ·Butter,1 ·Eggs}.

I am going to go to the supermarket to buy supplies, but I don’t know yet what I will make.

• Suppose I know that I will bake a cake or bake bread, but not both. What multiset of supplies do I need to purchase? How is this related to the multisets B and C?

• Suppose I want to bake a cake and bake bread. What multiset of supplies do I need to purchase? How is this related to the multisets B and C?