P$($A$)=0\mathrm{.}52,$ P$($B$)=0\mathrm{.}31$ and begin mathsize $20$px style text P$($A$\backslash$cap B$)=0\mathrm{.}23$ end text end style

Determine begin mathsize $20$px style text P$($ end text stack A union B right parenthesis with bar on top end style