Find the total number of polar molecules?

${\mathrm{SF}}_4 , {\mathrm{XeF}}_4 , {\mathrm{PCl}}_3{\mathrm{F}}_2 , {\mathrm{SF}}_6 , {\mathrm{XeF}}_2 , {\mathrm{BF}}_2\mathrm{Cl}, {\mathrm{BF}}_3$

${\mathrm{SF}}_4 ,{\mathrm{PCl}}_3{\mathrm{F}}_2 , {\mathrm{BF}}_2\mathrm{Cl}$ have dipole moment and have irregular structure. Rest of the molecule have symmetrical structure, thereby their net dipole moment becomes zero.