A company has two book stores. strore 1 and store 2, store 1 can supply 40 books per week and store 2 can supply 50 books per week. The demand from school A is 20 books per week , from schoolB is 15 books per week. from school C is 22 books per week and from school D is 18 books per week The cost of transportation in $ of one book to each school is as follows:

a.) Determine this is a balanced transportation problem., a problem with a shortage or a problem with excess supply. Type "Balanced", "Shortage" or "Excess"

b.) What is the minimal cost of the transportation? Round your answer to the nearest integer

c.) What is the optimal number of books supplied from store 1 to School A to secure minimal cost? Round your answer to the nearest integer

d.) What is the optimal number of books supplied from store 2 to School B to secure minimal cost??