已知$\Omega =\left\{(x,y)|x+y\le 8,x\ge 0,y\ge 0\right\}$$A=\left\{(x,y)|x\le 2,y\ge 0,3x-y\ge 0\right\}$,若向区域$\Omega$上随机投1个点P,则点P落入区域A的概率为 (      )

$\frac{1}{3}$ × $\frac{1}{2}$ ____ $\frac{1}{3}$             $\frac{1}{4}$ × $\frac{1}{3}$ ____ $\frac{1}{4}$

$\frac{1}{2}$ ×1____  $\frac{1}{2}$               6× $\frac{1}{2}$ ____6

9× $\frac{7}{2}$ ____9           $\frac{1}{2}$ × $\frac{2}{2}$ ____  $\frac{1}{2}$

$\frac{1}{3}$ × $\frac{1}{4}$ ____ $\frac{1}{3}$             3× $\frac{4}{5}$ ____3

$\frac{3}{4}$ × $\frac{3}{4}$ ____ $\frac{3}{4}$             5× $\frac{1}{3}$ ____5