I know molarity and can get molarity by this rule : mass/molar mass = Molarity × V (volume in litre , must be in Litre) so you are gonna get the mass/molarmass ÷ V (litre) and all this equals molarity. you can get Molality by this rule : mass/molar mass = Molality × mass of solvent (should be in Kg) , and it should be mass of solvent , neither solute nor solution. you are gonna get the mass(smaller mass in the problem)/molar mass = Molality × mass (the bigger one in the problem and if it's in gm you have to change it into Kg) so, mass/molarmass ÷ mass of solvent in Kg equals molality ! the measuring unit of Molarity is mole/litre and Molality mole/kg ^^
I dunno what happened to the answer
I edited it ^^