Calculate the minimum number of moles of R-Mg-X (Grignard reagent) required in the formation of a mole of cyclic Silicone.
 

$2 \mathrm{RMgX}+{\mathrm{SiCl}}_4\to {\mathrm{R}}_2{\mathrm{SiCl}}_2$

For cyclic silicone we need atleast 3 moles of R₂SiCl₂ and since for producing one mole of R₂SiCl₂ two moles of R−Mg−X is being utilised, hence for three moles of R₂SiCl₂ we will need six moles of R−Mg−X.