Molality of acetone?

Question

A solution is prepared by diluting 3.36 mL acetone, CH3COCH3 (d = 0.789 g/mL), with water to a final volume of 71.88 mL. The density of the solution is 0.993 g/mL. What is the molality of acetone in this solution?

Answer 1

i think it is not good answer.