MathDB
2019 Individual #14

Source:

May 1, 2022
2019 Individual

Problem Statement

A cue ball is shot at a 4545 degree angle from the upper right corner of a billiard table with dimensions 4 ft4\text{ ft} by 5 ft5\text{ ft}, as shown. How many times does the ball bounce before hitting another corner? Assume that when the ball bounces, its path is perfectly reflected. The final impact in the corner does not count as a bounce. [asy] size(120); draw((0,0)--(5,0)--(5,4)--(0,4)--cycle); label("55",(0,0)--(5,0),S); label("44",(0,0)--(0,4),W); filldraw(circle((0.4,3.6),0.4),black); draw((0,4)--(1.5,2.5),EndArrow); draw((1.5,2.5)--(4,0)--(5,1), dashed); draw(arc((0,4),1.25,315,270)); label(scale(0.8)*"4545^\circ",(0.2,2.8),SE); [/asy] <spanclass=latexbold>(A)</span>3<spanclass=latexbold>(B)</span>4<spanclass=latexbold>(C)</span>5<spanclass=latexbold>(D)</span>6<spanclass=latexbold>(E)</span>7<span class='latex-bold'>(A) </span>3\qquad<span class='latex-bold'>(B) </span>4\qquad<span class='latex-bold'>(C) </span>5\qquad<span class='latex-bold'>(D) </span>6\qquad<span class='latex-bold'>(E) </span>7