Chemistry help, molality and mole fraction, please

An aqueous solution is 5% NaCl by mass.
Calculate the molality of the solution
Calculate the mole fraction of the solution

Please explain how you found the answer, thank you!

Assume 1000 grams solution. Then

(0.05) * (1000 grams) = 50 grams NaCl
(0.95) * (1000 grams) = 950 grams H2O

(50 grams NaCl) * (1 mol NaCl / 58.44 grams NaCl) = 0.856 moles NaCl
(950 grams H2O) * (1 mol H2O / 18 grams H2O) = 52.78 moles H2O

molality = moles solute / kilograms solvent
molality = 0.856 moles NaCl / 0.950 kg H2O
molality = 0.901 m

mole fraction(solvent) = moles solute / (moles solute + moles solvent) = (52.78 moles H2O / (52.78 moles H2O + 0.856 moles NaCl)) = 0.984

mole fraction(solute) = (0.856 moles NaCl / (0.856 moles NaCl + 52.78 moles H2O)) = 0.016