It will take the slower computer 12 minutes to send the emails on its own.
It will take 4 minutes for the combined computer to send the emails
let
x = minute of the faster computer to send the emails on its own
Therefore,
[tex]\begin{gathered} \frac{1}{12}+\frac{1}{x}=\frac{1}{4} \\ \frac{x+12_{}}{12x}=\frac{1}{4} \\ \text{cross multiply} \\ 4(x+12)=12x \\ 4x+48=12x \\ 48=12x-4x \\ 48=8x \\ x=\frac{48}{8} \\ x=6 \end{gathered}[/tex]It will take 6 minutes for the faster computer to send the emails on its own.
