A 1.5 kg sample of -brass contains 0.45 kg of Zn, and the rest is Cu. The atomic weight of copper is 63.5 and zinc

A 1.5 kg sample of α-brass contains 0.45 kg of Zn, and the rest is Cu. The atomic weight of copper is 63.5 and zinc is 65.4. Write down the concentration of copper in α-brass, in wt%, WCu. Find the concentrations of copper and zinc in the α-brass, in wt%, XCu and XZn.