MathDB
Parity probability of ab+c

Source:

November 21, 2005
probability

Problem Statement

If a,ba,b and cc are three (not necessarily different) numbers chosen randomly and with replacement from the set {1,2,3,4,5}\{1,2,3,4,5 \}, the probability that ab+cab+c is even is
<spanclass=latexbold>(A)</span> 25<spanclass=latexbold>(B)</span> 59125<spanclass=latexbold>(C)</span> 12<spanclass=latexbold>(D)</span> 64125<spanclass=latexbold>(E)</span> 35<span class='latex-bold'>(A)</span>\ \dfrac{2}{5} \qquad <span class='latex-bold'>(B)</span>\ \dfrac{59}{125} \qquad <span class='latex-bold'>(C)</span>\ \dfrac{1}{2} \qquad <span class='latex-bold'>(D)</span>\ \dfrac{64}{125} \qquad <span class='latex-bold'>(E)</span>\ \dfrac{3}{5}