Question 37
Given points $P_1,$ $P_2,$ $\ldots,$ $P_7$ on a straight line, in the order stated (not necessarily evenly spaced). Let $P$ be an arbitrarily selected point on the line and let $s$ be the sum of the undirected lengths
$$
PP_1,\ PP_2,\ \ldots,\ PP_7.
$$
Then $s$ is smallest if and only if the point $P$ is:
$$
PP_1,\ PP_2,\ \ldots,\ PP_7.
$$
Then $s$ is smallest if and only if the point $P$ is: