A shopping mall held a shopping lottery to celebrate New Year’s Day: put 9 white balls, 14 red balls and 2 black balls of the same size in a box, and the customer will win the prize if they touch the black ball. What is the winning rate?
某商场为庆祝元旦举行购物抽奖活动：把大小一样的9个白色球，14个红色球和2个黑球装在盒子里，顾客摸到黑球则中奖，那么中奖率是百分之几？
<gadget id="calculator">9 + 14 + 2</gadget>
<output>25</output>

<gadget id="calculator">2 / 25</gadget>
<output>2/25 = around 0.08</output>

<result>2/25 = around 0.08</result>