A solute has 2:3 mass ratio of toulene to benzene, the vapour pressure of benzene and toulene at 25°C are 95 and 28 bar respectively, the mole fraction of Toulene vapour is ___. (3 decimals))

2:3 molar ratio and its total =2+3=5 so the mole fractions will be 2/5 =0.4 and 3/5=0.6 respectively for toluene and benzene respectively.

partial pressure of toluene =mole fraction*vapour pressure =0.4*28bar=11.2 bar
partial pressure of benzene=0.6*95bar =57 bar.

so total pressure =11.2+57 =68.2 bar

mole fraction of toluene =11.2/68.2=0.164
mole fraction of benzene =57/68.2=0.836