A chemist determines that 65.4g of Zinc reacts with 32.1g of sulfur to produce Zinc sulfide.  How many grams of Zinc Sulfide would be produced from 20.0g Zinc metal?  please help with the formula

First we need to take out its formula
            mass         moles
Zn        65.4 g      65.4 / 65.4= 1

S          32.1 g       32.1 / 32.1 =1
so the formula is ZnS
now 20 g of  Zn  x 1mole Zn / 65.4 g Zn   x 1mole of ZnS / 1mole of Zn  x  97.5 g ZnS / 1mole of ZnS =29.8 g ZnS