Let `CO_2=x`litre
`CO=(1-x)` litre
`underset(xlitre)CO_2overset(C)tounderset(2xlitre)2CO`
`underset(x)CO_2+underset(1-x)Co overset(C)tounderset(2x)2CO+underset(1-x litre)(CO)`
`2x+(1-x)=1.6`
`x=0.6litre`
volume of `CO_2=0.6` litre
Volume of `CO=(1-0.6)=0.4litre`