statement:1 A line L  passing through a point $P(5,3,1)$  intersects $L_1:\frac{x-7}{3}=\frac{y-7}{2}=\frac{z-3}{1}$  at A  and also intersects  $L_2:\frac{x-1}{2}=\frac{y+1}{4}=\frac{z+1}{3}$  at  B then distance between the points  P & B  is  ${\lambda }_1$
Statement:2  A plane passing through the point  $P(5,3,1)$ and containing the line
$\overline{\gamma }=7i+7j+3k+t(3i+2j+k)$  intersects the line  $\overline{\gamma }=i-j-k+\lambda (2i+4j+3k)$  at  Q, then distance between the points  P & Q  is  ${\lambda }_2.$ Then the value $\frac{{\lambda }_1+{\lambda }_2}{2}=\_\_\_$