How do you calculate the boiling point of a solution?
Well, the boiling point is elevated proportionally to the number of species in solution....
And this can be formally approached by Raoult's Law, which states that the vapour pressure of an ideal solution is proportional to the mole fractions of its constituents. For many (involatile) solutes, this means the observed boiling point of the solution is SLIGHTLY elevated with respect to the pure solvent, given that the mole fraction of the SOLVENT in the solution is SLIGHTLY reduced.
I suggest you consult your text for details of the calculation...