Calculate the molarity and mole fraction of acetone in a 1.77 m solution of acetone (CH3COCH3) in ethanol (C2H5OH). (Density of acetone = 0.788 g/cm3; density of ethanol = 0.789 g/cm3.) Assume that the volumes of acetone and ethanol add.

This is how my teacher explained how to figure the solution:
M = mole solute/ volume of total solution so

1) use moles of acetone to get volume of acetone using the density of acetone
2) kg Ethanol ( EtOH) to volume using the density. Assume if 2.29m than 2.29 moles of acetone in 1 kg of EtOH
3) add to get total volume of solution. You already have the moles of acetone from the molality.

Mole fraction = moles of solute/ total moles including moles of solute and solvent

I'm not looking for the answer, just a guide line of how to find the answer. I'm usually really good at chemistry, but this problem makes no sense to me.