MathDB
2020 Individual #7

Source:

April 30, 2022
2020 Individual

Problem Statement

John's digital clock is broken. It scrambles the digits of the time and displays them in a random order. For example, if the current time is 4:214:21, it could display 4:124:12, 2:142:14, or any other reordering of 44, 11, and 22. If his clock reads 6:716:71 one morning, how many possibilities are there for the correct time?
<spanclass=latexbold>(A)</span>0<spanclass=latexbold>(B)</span>1<spanclass=latexbold>(C)</span>2<spanclass=latexbold>(D)</span>4<spanclass=latexbold>(E)</span>6<span class='latex-bold'>(A) </span>0\qquad<span class='latex-bold'>(B) </span>1\qquad<span class='latex-bold'>(C) </span>2\qquad<span class='latex-bold'>(D) </span>4\qquad<span class='latex-bold'>(E) </span>6