On June 1st, there is a break-through story: put 20 table tennis balls of exactly the same shape, size, and weight into a bag, including 8 white ones, 5 yellow ones, 5 green ones, and 2 table tennis balls. a red one. If any ping pong ball is red, you can pass the level. What is the probability of passing the level once?
六一游园话动上，有一个闯关话动：将20个形状、大小，重量完全一样的乒乓球放入一个袋中，其中有8个白色的，5个黄色的，5个绿色的，2个红色的．如果任意摸出一个乒乓球是红色，就可以过关，那么一次过关的可能性为多少
<gadget id="calculator">2 / 20</gadget>
<output>1/10 = around 0.1</output>

<result>1/10 = around 0.1</result>