Molar ionic conductivity of a bivalent electrolyte are 57 and 73. The molar conductivity of the solution will be

According to Kohlrausch law of independent migration of ions, the molar conductivity of an electrolyte at infinite dilution is equal to the sun of the contributions of the molar conductivities of its ions.

Hence,

${\lambda }_{AB}={\lambda }_{A^{2+}}+{\lambda }_{B^{2-}}$ $=57+73=130S{cm}^2{mol}^{-1}$