2024 AMC 8 Problems/Problem 6

Revision as of 17:23, 25 January 2024 by Yoyo97 (talk | contribs)

Problem

Sergai skated around an ice rink, gliding along different paths. The gray lines in the figures below show foru of the paths labeled $P$, $Q$, $R$, and $S$. What is the sorted order of the four paths from shortest to longest?

$\textbf{(A)}\ P,Q,R,S \qquad \textbf{(B)}\ P,R,S,Q \qquad \textbf{(C)}\ Q,S,P,R \qquad \textbf{(D)}\ R,P,S,Q \qquad \textbf{(E)}\ R,S,P,Q$

Solution 1 (Analysis)

$R$ skips around the boundary of the rink, while $P$ goes around the whole boundary. Hence, the length of path $R$ is less than the length of path $P$. Now, using the fact that the hypotenuse of a right triangle is greater than both of its legs, it is clear that the path described in $S$ is longer than $P$. Finally, each V-shaped zag path from path $Q$ is longer than a diagonal in path $S$, so the length of path $Q$ is greater than that of $S$. Collectively, we obtain the answer $\boxed{\textbf{(D)}~R, P, S, Q}$.

Video Solution 1 (easy to digest) by Power Solve

https://www.youtube.com/watch?v=16YYti_pDUg