Recall,
#DeltaT_f = iK_fm#
Where #i# is the number of species in solution, #m# is the molality of the species, and #K_f# is the freezing point constant for that particular solvent (water, in this case).
Because #"LiCl"# dissociates in water solution into #"Li"^+# and #"Cl"^(-)# ions, #i = 2#.
Hence,
#DeltaT_F = 2 * (1.86°C)/m * (155g * ("mol")/(42.44g))/(575g * (kg)/(10^3g))#
#therefore T_f approx 23.6°C#
and by extension #-23.6°C# is the freezing point of that solution given your data.