Now Playing: 07-11-13 Marketplace

Would you pay $10 monthly to upgrade your phone twice a year? That's a plan T-Mobile is instituting. Microsoft has some plans of its own. The tech giant will revamp its structure and management. As senators squabble over student loans, we wonder why the math is so hard to do. Plus, a look at life in Egypt during its time of transition, why the smartest electrical grid in the world will be tested in Afghanistan’s hostile combat zones, and author Aifric Campbell discusses her new novel "On the Floor."