A mixture consisting of only sodium bromide (NaBr) and potassium bromide (KBr) weighs 0.8934 g. When the mixture is dissolved in water and an excess of silver nitrate is added, all the bromide ions associated with the original mixture are precipitated as insoluble silver bromide (AgBr). The mass of the silver bromide is found to be 1.5303 g. Calculate the mass percentages of sodium bromide and potassium bromide in the original mixture. Mass percent NaBr = % Mass percent KBr = %