An amount of 0.200 g of copper is dissolved in nitric acid. Excess ammonia is added to form Cu(NH3)42 and the solution is made up to 1 L. The following aliquots of the solution are taken and diluted to 10.0 mL: 10.0, 8.0, 5.0, 4.0, 3.0, 2.0, and 1.0 mL. The absorbances of the diluted solution were 0.500, 0.400, 0.250, 0.200, 0.150, 0.100, and 0.050, respectively. A series of samples was analyzed for copper concentration by forming the Cu(NH3)42 complex and measuring the absorbance. The absorbances were (a) 0.450, (b) 0.300, and (c) 0.200. What were the respective concentrations in the three copper solutions