There are 5 white balls, 2 red balls, and 3 yellow balls of the same size in a box. If one is drawn randomly, what is the probability of getting a red ball?
箱子里装有大小相同的5个白球、2个红球、3个黄球，任意摸出一个，摸到红球的可能性是多少．
<gadget id="calculator">5 + 2 + 3</gadget>
<output>10</output>

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

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