Balance the following equation and choose the quantity which is the sum of the coefficients of reactants and products
PtCl₄ + XeF₂ → PtF₆ + ClF +Xe

$\stackrel{+ 4}{\mathrm{Pt}}{\stackrel{-1}{\mathrm{Cl}}}_4+\stackrel{+2}{\mathrm{Xe}}\stackrel{-1}{{\mathrm{F}}_2}\to \stackrel{+6}{\mathrm{Pt}} \stackrel{-1}{{\mathrm{F}}_6} + \stackrel{+1}{\mathrm{Cl}}\stackrel{-1}{ \mathrm{F}}+\stackrel{0}{\mathrm{Xe}}$
 

After balancing other elements we get,
 

${\mathrm{PtCl}}_4+5{\mathrm{XeF}}_2\to {\mathrm{PtF}}_6+4\mathrm{ClF}+5\mathrm{Xe}$
The sum of the coefficients of reactants and products 1+5+1+4+5=16