For an alloy that consists of 90.1 g copper, 102 g zinc, and 5.92 g lead, what are the concentrations of (a) Cu (in weight percent), (b) Zn (in weight percent), and (c) Pb (in weight percent)? The atomic weights of Cu, Zn, and Pb are 63.54, 65.39, and 207.2 g/mol, respectively.