1. Given that $P$ is a point on the plane of $\triangle A B C$, satisfying
$$
\overrightarrow{P A}+\overrightarrow{P B}+2 \overrightarrow{P C}=3 \overrightarrow{A B} \text {. }
$$

Then the ratio of the area of $\triangle A B P$ to the area of $\triangle A B C$ is
$\qquad$
1. $1: 2$