Yield of reactions

i have a question, i cant understand how the answer is 20%
35g of molecular chlorine is reduced to 13,5g of zinc chloride using metallic zinc in excess
Zn+Cl2->ZnCl2
the answer is 20%
please help

What is the question?

35g of molecular chlorine is reduced to 13,5g of zinc chloride using metallic zinc in excess
Zn+Cl2->ZnCl2

This is not the question. This is the information before the question. What is it that has been asked?!

ok, didnt understad, dont be rude please
yhe question is what is the yield of the reaction

You start with 35 g chlorine which is equal to 1 mole.
You produce 13.5 g zinc chloride which is equal to 13.5 g / 65+(2 . 35) g/mol = 0,1 mol. But chlorine atoms in the ZnCl2 is double in terms of mole. It means you have 0.2 mole chlorine.
So, from 1 mole of chlorine, you have reached to 0.2 mole chlorine. The yield will be:
n(product)/n(reactant).100%=0.2/1.0=20%

the product isnt 0,1 mol and the reactant 0,2mol?
im confused
the yield is n product/n reactant or n reactant/n product ?

35g of molecular chlorine (Cl2) is 0.5mol. (MM of Cl x 2 = 35x2 = 70g/mol)
13.5g zinc chloride is 0.1 mol.
%yield rxn = 0.1/0.5 x 100 = 0.2 x 100 = 20%