p(5|x+y)=5/6×1/6+1/6×2/6=7/36=21/216
p(5|x+z ∧ 5|x+z)=5/6×1/36+1/6×4/36=9/216
p(5|x+y ∧ 5|x+z ∧ 5|y+z)=1/216
1-3×21/216+3×9/216-1/216=179/216