By the reaction of carbon & oxygen , a mixture of co & co2 is obtained. what is the composition by mass of the mixture obtaind when 20 grams of o2 reacts with 12 grams of carbon ?

M(O₂)=20g
M(O₂)=32.0 g/mol
n(O₂)=20/32.0=0.625 mol

m(C)=12 g
M(C)=12.0 g/mol
n(C)=12/12.0=1.0 mol

   2C     +     O₂      →    2CO
1 mol    0.625 mol        1 mol
         0.625-0.5=0.125 mol

      2CO    +         O₂       →        2CO₂
0.250 mol       0.125 mol       0.250 mol

n(CO)=1 mol - 0.250 mol = 0.750 mol
M(CO)=28.0 g/mol
m(CO)=0.750*28.0=21.0 g

n(CO₂)=0.250 mol
M(CO₂)=44.0 g/mol
m(CO₂)=0.250*44.0=11.0 g

What are the choices?