A liquid hydrocarbon mixture was made by adding 295 kg of benzene, 289 kg of toluene and 287 kg of p-xylene.  Assume there is no change of volume upon mixing, i.e., Vmix=0 , in order to determine: 

1. The species density of each species in the mixture. 

2. The total mass density. 

3. The mass fraction of each species.