How much chalcopyrite had to be mined to produce 100 pennies if reaction 1 had a percent yield of 63.00 % and all other reaction steps had yield of 100%?

1) Balanced chemical reaction 1:

2CuFeS₂ + 3O₂ → 2CuS + 2FeO + 2SO₂.  

Balanced chemical reaction 2: 2FeO + SiO₂ → 2FeSiO₃.  

Balanced chemical reaction 3: 2CuS → Cu₂S + S.

Balanced chemical reaction 4: Cu₂S + S + O₂ → 2Cu + 2SO₂.

m(Cu) = 3.0 g; mass of copper in one penny.  

n(Cu) = m(Cu) ÷ M(Cu).

n(Cu) = 3 g ÷ 63.55 g/mol.

n(Cu) = 0.047 mol; amount of copper in one penny.

2) From balanced chemical reactions: n(Cu) : n(CuFeS₂) = 1 : 1.

n(CuFeS₂) = 0.047 mol.

ω(CuFeS₂) = 63.00% ÷ 100%.

ω(CuFeS₂) = 0.630; a percent yield of chemical reaction 1.

m(CuFeS₂) = 0.047 mol · 183.54 g/mol ÷ 0.630.

m(CuFeS₂) = 13.692 g; mass of chalcopyrite for one penny.

m(CuFeS₂) = 13.6927 g · 100.

m(CuFeS₂) = 1369.27 g; mass of chalcopyrite for 100 pennies.

it is the most commonly accepted one