Defects per million opportunities $($dpmo$)=$

a$.($Number of defects discovered$)/$Opportunities for error $\backslash$times $1,000,000.$

b$.($Opportunities for error$/$Number of defects discovered$)\backslash$times $10,000,000.$

c$.($Number of defects discovered$)/$Opportunities for error $\backslash$times $100,000.$

d$.($Opportunities for error $\backslash$times Number of defects discovered$)/1,000,000.$