A bag contains a mixture of copper and lead BBs. The average density of the BBs is 9.60g/cm3. Assuming that the copper and lead are pure, determine the relative amounts of each kind of BB.

Express your answers numerically separated by a comma.

First, from reliable sources we get the densities of both the copper and lead. This will give us 8.96 g/cm3 and that of lead is 11.34 g/cm3. We assume that 1 cm3 of this certain mixture is composed of x cm3 of copper and y cm3 of zinc. Such that,

x + y = 1

and 9.60 = x (8.96) + y (11.34)

The values of x and y are 0.73 cm3 and 0.27 cm3. The masses are obtained by multiplying these values by the densities giving us with 6.54 g and 3.06 g.