Zoom International Math League

This question is about the online courses, which should be posted on a separate forum at https://classes.areteem.org/mod/forum/view.php?id=1827.

To answer your question, the point $P$ is inside the circle for this problem, so it is in between $A$ and $B$.  So if $AB=10$, and $AP=4$, we get $BP=6$.