Give the step-by-step reasoning process and then the final answer. Luther designs clothes for a high fashion company. His latest line of clothing uses both silk and cashmere fabrics. There are ten pieces made with silk and half that number made with cashmere. If his latest line has thirteen pieces, how many pieces use a blend of cashmere and silk?
Luther has 10 / 2 = 5 pieces made with cashmere. He has 13 - 10 = 3 pieces made without silk using only cashmere. Thus, Luther has 5 - 3 = 2 pieces made using a blend of cashmere and silk.
The final answer: 2.