calculate the mole fraction of benzene in a solution containing 40% by mass of toulene.?

let the mass of the total mixture be 100gm
mass of the benzene=40gm
mass of the toluene =60gm
molecular weight of benzene and toluene =78 and 92
mole fraction of benzene =mole of benzene/total mole
=40/78/(40/78+60/92)
=.44

Yes you are correct.I made the caculation using the total mass of the mixture is 100gm
According to the question
if the mass of touene is 100 gm
mass of benzene=40 gm
moles of toluene=92/100 =100/92 =1.08
moe of benzene=40/78 =.51
moe fraction of benzene=.51/(1.08+.51)
=.319
please check the answer and let me know.I think the answer is wrong