There are 6 number cards with "2", "3", "4", "5", "6" and "7" written on them respectively. What is the probability that one of them is a composite number drawn at random?
有6张数字卡片，上面分别写有"2"、"3"、"4"、"5"、"6"、"7"，任意抽出一张是合数的可能性是多少．
<gadget id="calculator">2 / 6</gadget>
<output>1/3 = around 0.333333</output>

<result>1/3 = around 0.333333</result>