Do relative permittivity and dielectric constant of a medium imply different physical quantities?

Three particles each of mass 1g and carryig a charge 'q' are suspendedfrom a common point by insulated massless strings, each 1oo cm long.If the particles are in equilibrium and are located at the corners of an equilateral triangle of sides of length 3cm,calculate the charge 'q' on each particle.{g=10 m/s^2}