MathDB
probability

Source: 2017 AMC 10A #15, AMC 12A #10

February 8, 2017
AMCAMC 10probabilityAMC 122017 AMC 10A2017 AMC 12A

Problem Statement

Chloé chooses a real number uniformly at random from the interval [0,2017][0, 2017]. Independently, Laurent chooses a real number uniformly at random from the interval [0,4034][0,4034]. What is the probability that Laurent's number is greater than Chloé's number?
<spanclass=latexbold>(A)</span> 12<spanclass=latexbold>(B)</span> 23<spanclass=latexbold>(C)</span> 34<spanclass=latexbold>(D)</span> 56<spanclass=latexbold>(E)</span> 78<span class='latex-bold'>(A)</span>~\frac12 \qquad <span class='latex-bold'>(B)</span>~\frac23 \qquad <span class='latex-bold'>(C)</span>~\frac34 \qquad <span class='latex-bold'>(D)</span>~\frac56\qquad <span class='latex-bold'>(E)</span>~\frac78