Response to the following problem:
Qualcomm Incorporated is a leading developer and manufacturer of digital wireless telecommunications products and services. Qualcomm reported the following inventories on September 26, 2010, in the notes to its financial statements:
  (in millions) September 26, 2010
Raw materials                             $ 15
Work in process                         284
Finished goods                           229
                                   528                                                                                                                                                       
a. Why does Qualcomm report three different inventories?
b. What costs are included in each of the three classes of inventory?