The lines L_1, L_2, …, L_20 are distinct. For n =1,2,3, …, 10 all the lines L_2 n -1 are parallel to each other and all the lines L_2 n pass through…

The lines $\displaystyle \mathrm{L}_1, \mathrm{~L}_2, \ldots, \mathrm{~L}_{20}$ are distinct. For $\displaystyle \mathrm{n}=1,2,3, \ldots, 10$ all the lines $\displaystyle \mathrm{L}_{2 \mathrm{n}-1}$ are parallel to each other and all the lines $\displaystyle \mathrm{L}_{2 \mathrm{n}}$ pass through a given point P . The maximum number of points of intersection of pairs of lines from the set $\displaystyle \left\{\mathrm{L}_1, \mathrm{~L}_2, \ldots, \mathrm{~L}_{20}\right\}$ is equal to $\displaystyle \_\_\_\_$.