Answer:
u = 6
Explanation:
When two triangles are similar, one can multiply one side by the ratio of the similitude to get find the length of the corresponding side in its similar triangle. The ratio of similitude can simply be defined as the scaling factor between two similar polygons. One can find the ratio of similitude by dividing two corresponding sides in similar triangles.
It is given that side NP is similar to OP. Therefore;

The ratio of similitude between the two given triangles is; 2
To find side NP, one must multiply it corresponding side, PL by the ratio of similitude;
PL * 2
= 3 * 2
= 6