There are 5 red balls, 3 white balls, and 2 yellow balls in a box. If you draw a ball at random, what is the probability of getting a yellow ball?
一个箱子里有5个红球，3个白球，2个黄球，任意摸出一个球，摸出黄球的可能性是多少．
<gadget id="calculator">5 + 3 + 2</gadget>
<output>10</output>

<gadget id="calculator">2 / 10</gadget>
<output>1/5 = around 0.2</output>

<result>1/5 = around 0.2</result>