MathDB
AMC 8 2004 Problem 21

Source:

July 22, 2011
probability

Problem Statement

Spinners A and B are spun. On each spinner, the arrow is equally likely to land on each number. What is the probability that the product of the two spinners' numbers is even?
[asy] defaultpen(linewidth(1)); draw(unitcircle); draw((1,0)--(-1,0)); draw((0,1)--(0,-1)); draw(shift(3,0)*unitcircle); draw(shift(3,0)*(origin--dir(90))); draw(shift(3,0)*(origin--dir(210))); draw(shift(3,0)*(origin--dir(330)));
draw(0.7*dir(200)--0.7*dir(20), linewidth(0.7), EndArrow(7)); draw(shift(3,0)*(0.7*dir(180+65)--0.7*dir(65)), linewidth(0.7), EndArrow(7));
label("11", (-0.45,0.1), N); label("44", (-0.45,-0.1), S); label("33", (0.45,-0.1), S); label("22", (0.45,0.1), N);
label("11", shift(3,0)*(-0.25,0.1), NW); label("22", shift(3,0)*(0.25,0.1), NE); label("33", shift(3,0)*(0,-0.3), S);
label("AA", (0,-1), S); label("BB", (3,-1), S); [/asy]
<spanclass=latexbold>(A)</span> 14<spanclass=latexbold>(B)</span> 13<spanclass=latexbold>(C)</span> 12<spanclass=latexbold>(D)</span> 23<spanclass=latexbold>(E)</span> 34 <span class='latex-bold'>(A)</span>\ \frac{1}{4}\qquad<span class='latex-bold'>(B)</span>\ \frac{1}{3}\qquad<span class='latex-bold'>(C)</span>\ \frac{1}{2}\qquad<span class='latex-bold'>(D)</span>\ \frac{2}{3}\qquad<span class='latex-bold'>(E)</span>\ \frac{3}{4}