The values of conductivity of some materials at 298 .15 K in Sm − 1 are 2 .1 × 10 3 , 1 .0 × 10 − 16 , 1 .2…

Molar conductivity is the conductance property of a solution containing one mole of the electrolyte, or it is a function of the ionic strength of a solution or the concentration of salt. 

${\mathrm{\Lambda }}_{\mathrm{m}} = \mathrm{K} / \mathrm{C}$

Where $\mathrm{K}$ is the specific conductivity and

$\mathrm{C}$ is the concentration in mole per litre.

Conductivity $\left({\mathrm{Sm}}^{-1}\right)$

$\left.\begin{array}{l}2.1\times {10}^3\\ 1.2\times 10\\ 3.91\\ 1\times {10}^3\end{array}\right\}$ conductors at $298.15\mathrm{K}$

$1\times {10}^{-16}$ Insulator at $298.15\mathrm{K}$

$\left.\begin{array}{l}1.5\times {10}^{-2}\\ 1\times {10}^{-7}\end{array}\right\}$ Semiconductor at $298.15\mathrm{K}$

Therefore number of conductors is $4$.