3) Three mixtures were prepared from three monodisperse polystyrene samples (with molar masses of 20000, 50000, and 150000g mol!) as indicated below: (50 points) (a) equal numbers of molecules of each sample, (b) equal masses of each sample, and (e) by mixing in the mass ratio 0.125:0.875 the two samples with molar masses of 20000 and 150000g mol!. For each of the mixtures calculate the number-average, , and weight-average, , molar mass and comment upon the meaning of the /values