If 406.6 g of a substance is dissolved in 879.1 g of cyclohexane solvent, the boiling point of the solution is 87.52 oC. Calculate the apparent molar mass (g/mol) of substance.

delta T = Kb*molality

delta T is difference between the normal boiling point and the b.p. shown in the problem Use this equation to solve for molality.
Then use molality = moles/kg solvent to solve for moles.

Then use moles = grams/molar mass to solve for molar mass.