Write down the numbers from 1 to 20 on a piece of paper, then make it into a paper ball, draw one at random, what is the probability of winning a composite number.
把1～20个数写在纸条上，再做成纸团，任意抽一个，抽中合数的可能性是多少．
<gadget id="calculator">11 / 20</gadget>
<output>11/20 = around 0.55</output>

<result>11/20 = around 0.55</result>